SIMPLE MACHINESWith Simple Machines, students explore the concepts behind six simple machines: the...
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SIMPLE MACHINES
Transcript of SIMPLE MACHINESWith Simple Machines, students explore the concepts behind six simple machines: the...
SIMPLE MACHINES
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Adapted from Schaumburg Illinois School District 54 Science Curriculum
Teacher’s Guide
Developed by:Ruth Hundley, Miriam Kitchen, Mary Anne Lucarelli,Sr. Mary Jane Nowakowski, Barbara Reifschneider
Piloted by:Peggy Amason, Joyce Beasley, Tracy Brubeck, Marilyn Burk,DIane Giedemann, Linda Kahley, Sara Manley, Carol Norris
M.A.S.H.Math And Science Hands-On
A Science Literacy Project
Funded By:Illinois State Board of Education
Sponsored By:Educational Service Center #16
Southern Illinois University, Edwardsville
ESC Project Team: SIUE Project Team:Director: Michael SchneiderCoordinator: Kathy DerangoConsultants: Barbara Goldenherseh Dr. Andrea Williams Joan Barrett
Director: Dr. David WinnettCoordinator: Ann ScatesSpecialist: Dr. Virginia BryanConsultants: Dr. William P. Ahlbrand Dr. Lela DeToye Dr. Thomas Jewett Dr. Robert Williams
In Cooperation with Regional SuperintendentsThe Honorable Harry Briggs, Jr.The Honorable Faye HughesThe Honorable Russell MasinelliThe Honorable Martha O’MalleyThe Honorable Larry Wolfe
Madison CountyMonroe/Randolph CountiesMacoupin CountySt. Clair CountyClinton/Washington Counties
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Table of ContentsM.A.S.H. at a Glance ................................................................................................................ 5Major Purpose ...........................................................................................................................7Objectives .................................................................................................................................7Teacher Background Information ............................................................................................. 8Safety Poster ............................................................................................................................ 9Classroom Management Techniques .......................................................................................10Resource List ...........................................................................................................................12Simple Machines Test ..............................................................................................................14Simple Machines Test Answer Key ........................................................................................... 17
ACTIVITIES:ACTIVITY #1: What Is A Force? ................................................................................................18ACTIVITY #2: What Is Work? .................................................................................................. 22ACTIVITY #3: What Is Friction? ................................................................................................27ACTIVITY #4: The Inclined Plane .............................................................................................33ACTIVITY #5: Wedge ...............................................................................................................37ACTIVITY #6: Screws ............................................................................................................. 39ACTIVITY #7: Levers .............................................................................................................. 45ACTIVITY #8: The Wheel & Axle ..............................................................................................51ACTIVITY #9: Wheels With Teeth ........................................................................................... 56ACTIVITY #10: Pulleys ............................................................................................................ 59Glossary ................................................................................................................................. 63
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Item Quantity10 Gallon Container 1**Balsa Wood (Cut 2” length) 10 pcBoard 16”x6”x1” (F) 6 pcCanning Jar Lids (widemouth) 1 pkg**Dishsoap, Dawn 1 btlDowel Rod 18”x3/4” (F) 2Dropper Bottles - 2 oz 3Egg Beater 1Game Markers 30Georello Gear Set 1*Index Cards - 3”x5” 30Plasticlay 1 lbPlastic Knives 15Magnets - Round 2Marbles 50**Masking Tape 1 roll**Paper Clips, regular 1 boxPaper Lunch Bags 30Pencil 30Pinewood Derby Car 1Pulley 2Pulley Cord (F) 5 yds*Rubberbands #16 30Rulers, Flat Wood 30Sandpaper/9x11/fine/120 grit 1Screwdriver, Phillips 10Screws - large thread, Phillips #14 - 1 1/2” 10Screws - small thread, Phillips, #6 - 1 1/2” 10Sherbert Lids, 1/2-Gal 2*Souffle Cups 3/4 oz 30Plastic Spoons 30Spring Scale 1**String 3 rollTeacher Guide 1Tongue Depressors 30Washers 1” o.d. 60**Wax Paper 1 roll
*Consumable **These items are consumable after a number of uses.
Supplies List
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M.A.S.H. at a Glance
Introduction
This section is written to provide you with a quick overview of the major curriculum elements around which the M.A.S.H. Kits are designed. The acronym M.A.S.H. represents Math And Science Hands-on. M.A.S.H. Kits were developed through a cooperative effort among local school districts, Educational Service Center Region 16, and Southern Illinois University at Edwardsville and originated from a regional Title II Science Cooperative. Funding by the Illinois State Board of Education through a Science Literacy Grant provided development, piloting, and revision of these kits, designed to meet the needs of teachers wanting to teach activity-based science in southwestern Illinois. Specifically, these needs were identified as: availability and cost of materials, lack of time needed to teach science inquiry, and teachers’ limited background in science. The thrust of development focused on these needs. The key elements of the M.A.S.H. Kit program are: scope and sequence of fundamental science concepts, alignment with state goals, emphasis on science process skills, cooperative learning, integration of language arts, opportunity to apply mathematics skills in real problem solving situations, teacher ownership, and alternatives in assessment. Special recognition should be given to the exemplary science kit program from Schaumburg Illinois School District 54, for their initial assistance and ideas.
Scope & Sequence
Each kit is developed around a fundamental theme in science that can be matched to concepts covered in most textbooks. Students explore these central themes as they complete approximately ten developmentally appropriate, process-based activities. The primary sequence introduces a theme from life, physical, or earth science. The intermediate kits further develop these same themes. Middle school kits continue to reinforce these same basic themes while utilizing a higher level of technology.
State Goals
The M.A.S.H. Kits were developed by Illinois educators primarily to assist classroom teachers in meeting the educational needs of their students. As a result, each investigation’s instructional objectives focus upon the Illinois State Goals for Learning. These goals include the basic concepts and fundamental skills in science, mathematics, social studies, language arts, fine arts, health, and physical education. Each investigation has been carefully selected to prepare students to meet or exceed Illinois goals. At the beginning of each of the activities the specific goals and objectives addressed by that activity has been identified and referenced.
Science Process Skills
The activities in the kits address the science process skills necessary for students to utilize when learning science: observe, measure, classify, infer, predict, communicate, formulate hypothesis, experiment, and interpret data.
Cooperative Learning
The instructional approach utilized in this curriculum is one of having students work in cooperative groups. It is recommended that the size of your cooperative groups not exceed four students. Many educational benefits occur when students work together in groups to investigate and solve problems. Cooperative learning more closely resembles the way individuals work together to solve problems in the real world. Another important reason for the use of cooperative groups is to make the acquisition, costs, and management of materials reasonable for the classroom teacher.
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Language Arts
Students read about, talk about, and write about the exciting science activities they are doing. This additional use of language along with the science investigation, reinforces the students’ understanding of the scientific principles being explored. Not only do many of the kits include their own science-related books, but an additional list of resources is located in the introduction of each kit guide.
Mathematics
Many of the science investigations result in an opportunity for the students to apply mathematics skills in a variety of ways. Students are encouraged to quantify their observations with metric measurements; record and report those same observations with charts, tables, and graphs. Often times students will need to apply mathematical operations to solve problems or answer questions.
Alternatives in Assessment
The Unit Test provided in this guide can be used to determine students’ understanding of the major concepts dealt with in the kit. Unit Tests use a variety of different questions such as multiple choice, fill in the blank, short answer, etc. The Unit Test may be given in a pre-post type format to determine: 1) the increase of students’ understanding as a result of this unit and 2) clarify students’ prior skills and knowledge to determine the direction instruction should take. Kits also include a performance based assessment that gives teachers the opportunity to observe what students actually can do with the science concepts and skills they have learned.
Teacher Ownership
The success of this program has been strongly dependent upon teacher ownership, especially at the very beginning of the projects’ early stages of developing, piloting, and editing of the core activities. Continued teacher ownership has resulted in the creation of extension activities which provide additional instructional opportunities in all curricular areas. These extensions continue to be developed by classroom teachers using the M.A.S.H. kits. Materials for these activities may or may not be included in the kit. If you have a great extension idea for a kit activity, please send it to us at Southern Illinois University Edwardsville, Box 2226, Edwardsville, IL, 62026.
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Major Purpose
Work is scientifically defined as the result of a force moving an object through a distance. It is a well-known fact that machines make work easier. While the wheels of a wheelbarrow make movement easier, the handle used to tilt the barrow makes moving heavy loads possible. Similarly, a ladder leaned against the side of a house makes getting to the roof easier than trying to vertically scale the side! These simple machines make work easier by changing the direction or the strength of a force that is applied to an object. Surprisingly, though, machines never reduce the amount of work to be done, but only make work easier by spreading it over a longer distance or by making it more convenient (by changing the direction, requiring less force) in some way.
With Simple Machines, students explore the concepts behind six simple machines: the inclined plane, the lever, the pulley, the screw, the wedge, and the wheel and axle. Whether it’s flying a paper airplane or lifting a certain object, the principles behind the machines are explored and applied. Simple Machines will help students complete work in the everyday world--whether it’s building a better snowman, or one day designing and building a bigger national monument. Who says all work and no play makes Jack a dull boy?
Objectives
After completing Colorful Chemistry, a student will be able to:
Generally:
• measure using the metric system• complete simple algebraic formulas when applicable• follow directions to complete simple scientific experiments• predict outcomes based on past observations• chart information
Specifically:
• define such terms as force, work, friction, inclined plane, lever, fulcrum, gears and pulleys
• construct a force gauge to measure the push and pull of an object• construct a simple lever• construct a simple wheel and axle
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Teacher Background Information:
A machine is any device that helps us do work. Some machines make work easier by changing the direction of the applied force. For example, it is easier to use a downward force to lift an object. Other machines reduce the amount of force that must be applied. For example, to lift a heavier person on a seesaw, a smaller person will use less force by sitting farther from the middle than her partner. Finally, some machines increase the speed or the range of movement, such as swinging a baseball bat or sweeping with a broom.
In any machine, there is a trade-off between force and distance. If a machine increases your force, it does so at the expense of you having to apply your force a longer distance and having the load move a shorter distance. Machines that increase the distance the load moves or the speed with which it moves do so at the expense of force. A greater force than would be necessary without the machine must be applied. The following formula should help you visualize this concept.
Force x Distance = Work
Suppose you need to do 20 units of work. One machine is designed so you only need to apply 2 units of force. However, you must apply this force over a distance of 10 meters. Force (2) x Distance (10) = Work (20). Another machine shortens the distance over which you need to apply the force to 5 meters. However, you have to use more force - 4 units worth. The equation thus is Force (4) x Distance (5) = Work (20). You do the same amount of work in each case, it’s your decision as to whether you prefer less effort or less distance.
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These safety rules may be discussed and posted during science activities or the teacher may have the class generate a list of safety procedures to follow.
SAFETY POSTER:
1. Listen to your teacher’s instructions.
2. Don’t touch or pick up any materials unless your teacher tells you to.
3. Follow directions.
4. Ask your teacher for help if you need it.
5. Cooperate with a partner or with your group.
6. Never put anything in or near your eyes or mouth.
7. Clean up work area and return all materials to their proper places.
8. Always walk in the science area.
9. Talk quietly in groups.
10. Tell your teacher immediately in case of accidents.
11. BE CAREFUL!!!
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Cooperative Learning: Classroom Management Techniques
1. In order for your students to complete the activities successfully, it is essential that they know, and follow, the ten rules for group work:
• Move into groups quietly, without bothering others• Use quiet voices• Stay with your group• Everyone does a job• Everyone shares the work• No one is bossy• Everyone shares materials• Everyone shares ideas• Take turns talking• Care about others’ feelings
2. Initially avoid competition between groups. This can be accomplished by carefully selecting groups in a variety of manners — randomly (i.e. by birthdays), by students’ abilities, or by allowing the students to choose groups for themselves. It is important to note that if the final technique is used to form groups, the students must be made aware that if their group does not perform adequately or productively, alternative selection methods will be employed (i.e. teacher selection).
3. Clearly define the task to be done.
4. Be sure there is a “product” connected with the group activity.
5. In setting time limits, allow too little time rather than too much time for the group to finish.
6. Each person in the team should play an active role. Regular rotation of roles should occur to give each student the opportunity to play a different role. Roles students can have are:
Principal Investigator:
This person keeps the group members on task, makes sure the activity is understood by all and is completed. Any questions will be immediately clarified with the teacher.
Materials Manager:
This person obtains all supplies the group needs. If the group is large enough, a second Materials Manager can be assigned to be responsible for returning materials to the supply area and having the group clean up its work area.
Recorder/Evaluator:
This person writes down responses that team members have formulated. This person notes how well group members perform their responsibilities, contributing to the overall performance and outcome of the group.
Reporter: This person writes down the group’s conclusions and reports to the class. The reporter may also need to record the group’s data on a class graph or chart. If the group is large enough, two Reporters can be assigned — one to record conclusions and chart data, the other to present their findings to the class.
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7. Follow the Five C’s of Group work to have a safe, and FUN, science activity:
Caution: Laboratory group work requires caution in every part. Safety instructions should be followed and a safety checklist should be implemented before each activity.
Cooperate: To ensure successful group work, each member must cooperate with the other members of the group.
Contribute: Each member must make an effort to contribute something to the group.
Control: Group work requires control over our body movements, voices, and actions. To avoid chaos in the classroom, control must be practiced by each member of the group.
Clean-Up: Each group member must do his or her part to clean up after the activity. Students must make sure the work area is clean and all materials are put away.
8. The culmination of a group activity should be a time of sharing and evaluating how well group members worked together as well as examining the groups’ end results or products.
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These books may be read during the unit:
1. Simple Machines by Rae Bains2. Andrew Henry’s Meadow by Doris Burn3. Sparrow Socks by George Selden4. Me & My Flying Machine by Marianna and Mercer Mayer5. The Furious Flycycle by Jan Wahl6. Chitty, Chitty, Bang, Bang by Ian Fleming7. The Wright Brothers at Kittyhawk by Donald Sobol8. Homer Price by Robert McCloskey
Computer software available: Physical Science Series- Machines, Work, and Energy from Educational Activities, Inc.
Use the game Mousetrap by Ideal as a demonstration or to play.
Resource List
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This poem may be done as a rap.
SIX SIMPLE MACHINES
We’ll look at six, six simple machines,And they help us with the work that we do.
We’ll look at six, six simple machines,And they’ll be helpful to me and you.
The first is the lever to lift and pry. The second is the inclined plane:
Since it’s sloped like a hill,It can lift things high.
The third is the wedge with a tapering edge.The fourth has threads and turns -- it’s a screw.
And the fifth is the axle and wheel. Sixth is the pulley-- it’s perfect for you
To use in connection with changing direction.
We’ll look at six, six simple machines, And they help us with the work that we do.
We’ll look at six, six simple machines,And we’ll take a look at these with you.
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SIMPLE MACHINES TEST NAME: ____________________________
Write the letter of the correct word in the space before each question. One answer will be left over.
a) screw f) load
b) inclined plane g) wheel and axle
c) fulcrum h) pulley
d) wedge i) lever
e) friction j) force
1. ________ the object to be moved by a lever
2. ________ a simple machine that uses a rope and a grooved wheel
3. ________ a knife blade is an example of a(n) ___________________
4. ________ a ramp is an example of a(n) ___________________________
5. ________ an example of this is a seesaw
6. ________ a lever tilts back and forth on its ___________________
7. ________ an inclined plane wrapped around a post
8. ________ a push or a pull
9. ________ a force that slows down objects in motion
Place the letter of the best choice in the blank.
10. ________ In a wheel and axle, ________ force is needed to turn the wheel than is needed to turn the axle.
a) more b) less
11. ________ Flags can be raised using a
a) screw b) pulley c) lever
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12. ________ More work is being done when a person is
a) lifting a 10 lb. weight b) holding a 50 lb. weight c) lifting a 20 lb. weight
13. ________ Which surface would have the least friction?
a) wax paper b) sandpaper c) sidewalk
14. ________ More work is being done when a person is
a) holding a book b) reading a book
c) lifting a book 1 meter d) lifting a book 2 meters
Place an “L” by the items that are levers.
15. ________ paper punch
16. ________ nail
17. ________ baseball bat
18. ________ pliers
19. ________ door handle
20. ________ ramp
Answer the questions below.21. Which will travel a farther distance when turned- an axle or a wheel and axle?
22. Which gauge shows the most force being used?
-- 0
-- 1
-- 2
-- 3
-- 4
-- 5
-- 6
-- 0
-- 1
-- 2
-- 3
-- 4
-- 5
-- 6
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23. Which wagon would take the most force to move?
A. B. C.
24. Which inclined plane reduces force the most?
A. B.
25. Which picture shows where the load would be easiest to lift?
A. B.
26. Which screw was made from a steep inclined plane?
A. B.
27. Which screw would take the least amount of force to screw in?
A. B.
Load Load
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SIMPLE MACHINES TEST ANSWER KEY
1. f2. h3. d4. b5. i6. c7. a8. j9. e10. b11. b12. c13. a14. d15. L16. -17. L18. L19. -20. -21. wheel and axle22. a23. c24. a25. b 26. a27. b
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ACTIVITY #1: What Is A Force?
TIME: 50 Minutes
OBJECTIVES: Students will learn that a force is a push or a pull. Students will construct a force gauge to measure the push or the pull on an object.
TEACHER BACKGROUND INFORMATION: A force is a push or pull that, when applied to objects, will cause them to move. The greater the mass of the object, the greater the force required to move it. Examples of forces are wind, water, gravity, magnetism, and muscles.
When using the force gauge in the this activity, some items may have to be wrapped Christmas present style with string so the paper clip can be attached. You can either bring in items yourself or have students bring in their own lightweight items. One suggestion is to use milk cartons filled with small weights such as washers, marbles, or even sand. In any case, it is recommended that the teacher test items ahead of time to make sure none of them exceed the lifting capabilities of the force gauge. The force gauges and lightweight items should be kept at school because they will be used in subsequent activities. NOTE: When the force gauges are used to lift items, they should be raised with a slow, even motion and never jerked.
MATERIALS: Index card Paper clip Rubberband Ruler (all 1 per student) 2 magnets String Spring scale (all for teacher demonstration)
(The teacher should demonstrate how to clean the hand lenses before giving them to the students.)
TEACHER/STUDENT PROVIDED MATERIALS: Scissors Stapler- more than 1 if your students are able to staple with ease Stick or dowel rod for each pair of students Plastic pinwheel 2 lightweight items per pair
PROCEDURE:
1. Push or pull your desk chair across the floor a short distance. Ask students what you did to move the chair. They should respond “you pushed it” or “you pulled it”. Introduce the word force as a push or a pull.
2. Let the students try examples where their muscles are used to push or pull.a) Working in pairs, have students sit face to face with toes touching, knees bent. Grasp hands. One student lies back and the other pulls him back up. Take turns pulling each other to the floor and back up again. (Like a modified sit-up)
b) Working in pairs, have students sit on the ground facing each other with the soles of their shoes braced together. Have them hold onto a stick and pull, trying to get their opponent to slide forward or even stand up on their feet.
c) Working in pairs, have students stand back to back and link their arms. Each student tries to push the other across a marked off area.
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d) If weather permits, take students outside to a grassy area for a tug-of-war. Ask them how they will know which side used the greater force? How would they tell if both sides used equal force?
3. Brainstorm other forces besides muscles that might not be so obvious. Then demonstrate the force of wind by using the pinwheel; the force of gravity by dropping something; and the force of magnetism by first bringing one magnet toward another with opposite poles (so they attract), and then switching to the same poles (so they repel).
4. Tell students that now they will construct a scientific instrument to measure how much force they exert when they pull something. Read through the directions for constructing a force gauge on Student Activity Sheet 1A. Help the students if they have difficulty.
5. When all students have completed their gauge, demonstrate the spring scale to them. Give them ample opportunity to see that the indicator must start at zero and that it moves to a number that shows the force you used to pull something.
6. Have them pick 2 items of fairly light weight they want to lift (pull up) with their force gauge. They should record on Student Activity Sheet 1B the names of their items and to what number the rubberband stretched.
7. Discuss the results. Explain that the amount of force needed to lift both objects at once is the same as each individual force added together.
FORMATIVE EVALUATION: Students will be evaluated on the construction of their force gauge and the completion of sheet 1B.
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Name _______________________________________
Making A Force Guage
MATERIALS: index card, paper clip, stapler
PROCEDURE:
1. Staple the rubberband at the top of the index card.2. Open up a small paper clip and hook one end around the rubberband. The other end of the
paper clip should be stretched until it reaches the end of the card. Form a hook in this end, too.
3. Lift the card and let it dangle from your fingers so the rubberband lays to its full length but is not stretched.
4. Hold the rubberband flat against the index card, and draw a line on the card at the end of the rubberband.
5. Using a centimeter ruler, start at the line you made and make a mark every centimeter on the card.
6. Write 0 by the first line and continue with 1, 2, 3 etc. until all the marks are numbered.
rubberband
staple
index card
hold cardup
mark whererubberbandends
paper clip
mark scale in cm
0123456
Step 1 Step 2 Step 3
Step 4 Steps 5 & 6
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Name _______________________________________
How Much Force Is Used?
MATERIALS: force gauge, 2 lightweight items
PROCEDURE:1. Lift each item with your force gauge.
2. Write the name of the item and the force you used in the chart below.
ITEM FORCE
1. Which item took the most force to lift?
2. How do you know?
3. Predict the force needed to lift both items at the same time. Write your guess.
4. Try it. Write down how much force it took.
5. Did you guess right?
6. Add together the force it took to lift each object. Is the answer the same as #4?
7. Should it be?
Why or why not?
8. Write the definition of force:
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ACTIVITY #2: What Is Work?
TIME: 35 Minutes
OBJECTIVE: Students will learn that work occurs when a force moves an object through a distance. They will use a force gauge and the formula for work to determine the amount of work done.
TEACHER BACKGROUND INFORMATION: In the strictest scientific definition, work is done when a force moves an object through a distance. (In other words, when a push or a pull causes motion.) If you push with all your might against a brick wall that never moves, you are not doing any work. Although you exerted a force, the object did not move. The same is true if you lift a pile of books. You do work when you lift the books, but you don’t do anymore work if you continue to hold them for 10 minutes.
MATERIALS: Student force gauges Student Activity Sheet 2 (Version 1 or 2 depending on multiplication skills of the students) Masking tape 2 lightweight items per student
TEACHER/STUDENT PROVIDED MATERIALS: 1 heavy book, 1 light book, Meter stick
PROCEDURE:
1. In advance, use masking tape, a meter stick, and a marker to mark the walls around the room in heights of 30 centimeters and 60 centimeters.
2. Slide a chair across the floor a short distance. Then take a stance, put the chair against the wall, and push the chair very hard into the wall. Make sure the students know you are pushing HARD. Ask the students when you did the most work; pushing the chair across the floor or pushing it against the wall. Explain that work is done when a push or a pull moves something a distance. If something doesn’t move, work is not being done. Even though you push very hard against the wall, since the chair did not move, work was not being done. Pushing the chair moved the chair, so work was being done.
3. Have 2 students come to the front of the room. Have 1 student hold a heavy book, and the other pick a light book up off your desk. Ask the class who did the most work. Explain that because the one student only held the book and didn’t move it, he did no work. The student that moved the book up and off the desk was the only one to do work.
4. Tell the students that they are going to use their force gauges to lift some items and measure the amount of force used. Then they will multiply some numbers to figure out when they did the most work. NOTE: Since many second graders are not ready for multiplication until the spring, an alternative activity sheet (Version 2) with different directions is provided.
5. Read through Student Activity Sheet 2 with the students so they know what to do. They should not worry about filling in the “WORK” column until after they have recorded all their data.
6. When students have finished, discuss the results. Explain that more work is done if you lift the same object a greater distance (part 1). More work is also done if you lift 2 objects the same distance but one of them is heavier (part 2).
FORMATIVE EVALUATION: Students will be evaluated on the completion of Student Activity Sheet 2.
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Name _______________________________________
Version #1: When Is More Work Done?
MATERIALS: force gauge, 2 lightweight items, a 30 centimeter and 60 centimeter height
PART 1 PROCEDURE:
1. Lift your first item with your force gauge from the floor to the 30 centimeter height.2. Write the name of the item and the force used in the chart below.3. Do the same with the second item.
ITEM FORCE DISTANCE WORK
30 cm
30 cm
4. For the first item, multiply the number in the “Force” column by the number in the “Distance” column. Write the answer in the “Work” column.
5. Do the same thing for the second item.
6. The biggest number in the “Work” column shows where the most work was done. Which item took the most work to lift?
7. Write the definition of work.
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PART 2 PROCEDURE:
1. Pick 1 item to lift with your force gauge.2. Lift it 30 centimeters.3. Record the name of the item and the force used in the chart below.4. Lift the same object to a height of 60 centimeters.5. Record the name of the item and the force used in the chart below.
ITEM FORCE DISTANCE WORK
30 cm
60 cm
6. For the first row, multiply the number in the “Force” column by the number in the “Distance” column. Write that answer in the “Work” column.
7. Do the same thing for the second item.8. The biggest number in the “Work” column shows where the most work was done.9. Where did you do more work- lifting the item 30 cm or 60 cm?
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Name _______________________________________
Version #2: When Is More Work Done?
MATERIALS: force gauge, 2 lightweight items, a 30 centimeter and 60 centimeter height
PART 1 PROCEDURE:
1. Lift your first item with your force gauge from the floor to the 30 centimeter height.2. Write the name of the item and the force used in the chart below.3. Do the same with the second item.
ITEM FORCE DISTANCE WORK
30 cm
30 cm
4. You had to move each item the same distance, 30 centimeters. The item that took the most force to lift is where the most work was done.
5. Put a check in the “Work” column by the item that shows where you did the most work.
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PART 2 PROCEDURE:
1. Pick 1 item to lift with your force gauge.2. Lift it 30 centimeters.3. Record the name of the item and the force used in the chart below.4. Lift the same object to a height of 60 centimeters.5. Record the name of the item and the force used in the chart below.
ITEM FORCE DISTANCE WORK
30 cm
60 cm
6. You had to move the item twice as high when you lifted it 60 centimeters.7. Put a check in the “Work” column that shows which time you had to do the most work.8. Write the definition of work.
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ACTIVITY #3: What Is Friction?
TIME: 45 Minutes
OBJECTIVE: Students will learn that friction is the force that stops or slows down motion. Students will learn which surfaces have the least friction. They will identify ways friction may be reduced.
TEACHER BACKGROUND INFORMATION: Friction occurs whenever one object moves over another. Anytime force is applied to move an object, the force of friction opposes it. For motion to occur, the applied force must be great enough to overcome the friction. Friction is also the force that slows down or stops objects in motion.
The amount of friction depends on the type of surfaces that touch each other. There is more friction when an object moves over a rough surface than a smooth one. Lubricants such as soap, oil, and ball bearings reduce friction.
Friction can be helpful or harmful. For example, without friction we would be unable to walk across the floor or ride a bike. Friction can be harmful, though, since it causes heat and the wearing away of surfaces in contact.
The experiments in this lesson should be set up at stations. Task cards for each activity are included at the end of the lesson. The stations should accommodate 5 or 6 students at a time. Students should spend 5-7 minutes at each station. Use a bell or a signal to time the move to the next station.
HINTS FOR STATIONS:
Station 1 - Explain that all students at this station do the first step and then the remaining ones. This will avoid having to wipe the door handle off for each student. The knob should be wiped off between groups.
Station 2 - Placing 24 marbles at this station will allow six children to do it at once. Marbles should be wiped off between groups. Fill one of the dropper bottles with dish soap.
Station 3 -Placing 12 lids at this station will allow 6 groups to start with fresh (no soap on them) lids. Again, all students at the station should first feel the lids without the soap and then add the soap.
Station 4 - The remaining marbles should be placed at this station. The sherbert lids are used like the bread in a sandwich and the marbles are the filling. The lids should be placed so that the marbles fit in the groove that would normally fit on the tub of sherbert. Use the school book at this station.
Station 5 - You will need to place a piece of masking tape on the floor or table to be the starting line. You will also need a ruler to measure the distance the car travels.
Station 6- String will need to be tied around the books, Christmas-present style. Make sure the books are not too heavy to be registered on the force gauge.
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MATERIALS: 2 sheets sandpaper 2 sheets wax paper Plastic spoon (1 per student) Dish soap 3 dropper bottles (to place dishsoap in) 50 marbles 2 plastic sherbet lids 12 canning lids String 2 student force gauges Paper towels for Stations 1 and 2, ruler 2 lightweight books 1 school book Pinewood derby car
STUDENT PROVIDED MATERIALS: pencil with eraser and paper
PROCEDURE:
1. Introduce friction by having the students rub their hands together for about ten seconds. They should feel heat. Tell them the heat was caused by friction - the force that slows down objects in motion. In this case, the friction caused by one hand rubbing against the other was responsible for the heat they felt.
2. Distribute the plastic spoons and let students see who can get a spoon to hang on their nose the longest Allow students to try to get the spoon to hang from the end of their noses. Then suggest to anyone having problems that they try breathing on the spoon first. The force that allows the spoon to hang from their nose is friction. The water vapor from breathing on the spoon increases the friction, much like trying to slide down a slightly wet slide.
3. Have the students take a sheet of paper and rub their eraser over it. Have them explain why they see tiny pieces of the eraser on the paper. (Friction caused by the movement of the eraser against the paper wears away both the eraser and the paper.)
4. Break the students into groups and allow them time to do the activities at each station. Remind them to complete Student Activity Sheet 3 at each station. Then bring all of them together for a class discussion on what they learned at each station.
5. Mention that machines are affected by friction because friction causes things to get hot and wear out when they rub against each other. Discuss why they decrease friction by using lubrication on their bicycles or various machines mom and dad use around the home- oil in cars, etc. All machines with parts which slide over each other need oil or grease lubrication. Without it, they would rub and could get so hot they would melt. Overall, friction reduces the efficiency of a machine by wearing out parts and wasting energy.
6. Point out to the students that there are some good things about friction. Without friction we couldn’t walk without slipping, turn a door handle, write with a pencil, use brakes on a bike or car, or make tires move down the road.
FORMATIVE EVALUATION: Students will be evaluated on the completion of Student Activity Sheet 3.
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STATION 1
All students should do the first step before doing the others.
a) Open the door by turning the knob.
b) Place a drop of dishwashing soap on your hand and rub your hands back and forth.
c) Try opening the door again. Was it harder or easier with the soap?
d) Wipe off the door handle for the next group.
STATION 2
a) Rub the palms of your hands together for about 10 seconds.
b) Place 4 marbles in your hands and rub your hands together.
c) Place a drop of dishwashing soap on your hands. Rub your hands together. How does this compare to the marbles?
d) Place the marbles in your hands (don’t wipe off the soap) and rub your hands together.
e) Which time did you feel the least amount of heat - with the marbles, the soap, or both the marbles and the soap?
f) Wipe off the marbles for the next group.
STATION 3
All students should do the first step before doing the others.
a) Place 2 jar lids together so that the shiny side is up against the side with the red rubber rim.
b) Turn them back and forth against each other.
c) Squeeze dishwashing soap on top of the red rubber rim and place it against the shiny side.
d) Was it easier or harder to turn the lids back and forth with the soap?
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STATION 4
a) Spin the book on top of the table.
b) Put one sherbert lid on the table upside down, place marbles around the groove of the lid, and put the other sherbert lid on top, right side up.
c) Put the book on top of the sherbert lid and marble “sandwich” and try to spin it.
d) Was it easier or harder to spin the book using the marbles and the lids?
STATION 5
a) Turn the car upside down and place it at the starting line.
b) Give it a push and measure with a ruler how far it goes.
c) Turn it right side up and place it at the starting line.
d) Give it a push and measure with a ruler how far it goes.
e) Did it move more or less when you used the wheels?
STATION 6
a) Attach your force gauge to the string tied around the book.
b) Drag the book across the sandpaper with a steady motion. Write down the force you used.
c) Drag the book across the waxed paper with a steady motion. Write down the force you used.
d) Which surface took the least force to drag the book across?
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Name _______________________________________Activity #3: What Is Friction?
Circle the correct answer for each station. Then answer the questions.
STATION 1 - Was it harder or easier to open the door with soap on your hands?
harder easier
How did you reduce friction at Station 1?
STATION 2 - When did you feel the least heat or friction?
marbles soap marbles and soap
How did you reduce Friction at Station 2?
STATION 3 - Was it harder or easier to turn the lids back and forth when soap was added?
harder easier
How did you reduce friction at Station 3?
STATION 4 - Was it harder or easier to spin the book using the marbles and sherbert lids?
harder easier
How did you reduce friction at Station 4?
STATION 5 - When did the car move the farthest?
with wheels without wheels
How did you reduce friction at Station 5?
STATION 6 - Which surface took the least force to drag the book across?
waxpaper sandpaper
How did you reduce friction at Station 6?
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1. Write the definition of friction.
2. What are 3 ways to reduce friction?
a)
b)
c)
3. Name 3 things we do that require friction.
a)
b)
c)
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ACTIVITY #4: Will it Dissolve?
TIME: 30 Minutes
OBJECTIVE: Students will measure the force needed to lift an object with and without an inclined plane.
TEACHER BACKGROUND INFORMATION: An inclined plane is a sloping surface that goes from a lower level to a higher level. Children have had experiences with inclined planes such as walking up a hill, stairway, or ramp; coasting down a hill on their bike, or riding in a car on an exit ramp from a highway.
In this experiment, students will measure the force needed to lift an object straight up as opposed to using an inclined plane. Remember - less work is not being done with an inclined plane. Lifting straight up requires a lot of force in a short distance. An inclined plane uses less force over a longer distance. (According to the formula for work, Force x Distance = Work. Think of 5 units of force x 4 feet for lifting straight up, versus 2 units of force x 10 feet for an inclined plane. You still did 20 units of work!)
MATERIALS: Six 16” x 6” x 1” boards and something to rest them on (a stack of books, edge of Rubbermaid tub, etc.) Student force gauges String Lightweight item for lifting
PROCEDURE:
1. Introduce inclined planes by mentioning the examples listed above in “Teacher Background Information”. Let students brainstorm others.
2. Tell students that they will measure the amount of force used to lift something with and without an inclined plane. Although not critical to the results of this activity, it is good scientific procedure to have the students lift the item straight up to the same height they would slide the item when using the inclined plane. This becomes essential if you plan to talk about step 4 below. Divide students in groups so that the numbers are evenly split among the 6 boards.
3. When students are finished with Student Activity Sheet 4, bring them back as a class to discuss the results.
4. If you feel students understand the concept of Force x Distance = Work, have them record their numbers for force and distance to show them that the amount of work done was the same. This will require measuring the length of the inclined plane (Distance) and the height to which the item was lifted without the board (Distance). The force used each time is then multiplied by the appropriate distance. See sample on next page.
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Note: This will not always work, due to the friction between the board and the object being pulled.
FORMATIVE EVALUATION: Students will be evaluated on the completion of Student Activity Sheet 4.
LANGUAGE ARTS EXTENSION: The U.S. patent office was formed in 1790. A few years later it was closed because it was felt that everything that could be invented had been! It was, of course, reopened and there have been countless inventions since that time. Have students choose an invention from the time line on the next page or chose another and write a report to be read to the class.
Dis
tanc
est
raig
htup 1
mDistance 2 m
inclined
plane
F x D = W F x D = W3 x 2 = 6 6 x 1 = 6
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INVENTOR
Unknown
Unknown
Unknown
Unknown
Archimedes
Romans
Italians
Huygens
Savery
Hargreaves
Otis
Morse
MacMillan
Sholes
Daimler
Booth, Hubert
Hurley Co.
Baird
Whittle
Sikorsky
DATE OF INVENTION
Stone Age
3000 BC
800 BC
250 BC
100 BC
1335 AD
1656 AD
1698 AD
1764 AD
1835 AD
1837 AD
1839 - 40 AD
1868 AD
1885 AD
1901 AD
1907 AD
1926 AD
1930 AD
1939 AD
1942 AD
INVENTION
lever, wedge, inclined plane
wheel and axle
pulley
water screw
water-wheel
mechanical clock
pendulum clock
steam engine
Spinning Jenny
steam shovel
telegraph
bicycle
typewriter
motor car
vacuum cleaner
electric washing machine
television
jet engine
helicopter
electric computer
TIME LINE OF MACHINES INVENTED
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Name _______________________________________
Activity #4: The Inclined Plane
MATERIALS: 16” x 16” x 1” board, force gauge, string, lightweight item
PROCEDURE:
1. Set the board at a slant to that it rests on the support your teacher has given you.2. Attach your lightweight item to your force gauge. Use string to wrap your item Christmas-
present style if you have to. Ask your teacher for help if you have problems.3. Place the item at the bottom of the board and slowly pull it to the top of the board.4. Record the force used in the chart on the next page.5. Place the item on the desktop. Slowly lift it straight up to the same height the inclined
plane was.6. Record the force used in the chart on the next page.7. Compare the 2 numbers. When did you use the least force?
8. If you had your choice, which method would you pick so that the least force is used?
9. Write the definition of an inclined plane.
METHOD FORCE USED
Inclined Plane
Straight Up
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ACTIVITY #5: Does it Mix?
TIME: 45 Minutes
OBJECTIVE: Students will learn that wedges are two inclined planes put back to back. Students will see that wedges reduce the force necessary to move an item through a medium.
TEACHER BACKGROUND INFORMATION: Many variables can influence the success of this activity. In most cases, the blunt nosed airplane will not fly as far as the wedge-nosed one. Factors such as differences in paper airplane styles and manner of throwing may affect the results.
It is suggested that you set up a “landing strip” in the gym with distances marked off or with measuring tapes laid on the floor. The students will thus have plenty of room to throw their airplanes and measure the distance.
MATERIALS: 15 plastic knives 15 blunt edge rulers 15 small balls of clay Student Activity Sheet 5
TEACHER/STUDENT PROVIDED MATERIALS: Scissors 2 pieces of paper per student Meter stick or measuring tape
PROCEDURE:
1. Draw a wedge on the board and see if students can see where the simple machine they just learned about is present in the wedge. They should note that a wedge is 2 inclined planes placed back to back.
2. Give each pair of students a piece of clay, a knife, and a blunt edge ruler. (An apple piece may be substituted for the clay for a better effect.) They should try to cut the clay (or apple) with the ruler first and then the knife. Discuss which was easier (the knife) and why (it has a wedged surface for cutting).
3. Distribute Student Activity Sheet 5. Put students in group of 2. If possible, let children go in the gymnasium to fly their paper airplanes. Have each group construct 2 identical paper airplanes. Cut the nose off one, and measure the distance each one flies in two trials (let each student fly both the wedge and non-wedge airplane once). They should be able to see that the wedge-nosed flew farther each time. If not, you should introduce the concept of averaging. Most students will be unable to average the trials, so you will have to help them or let them use calculators if they are available.
4. When students finish, explain that when both are thrown with the same amount of force, the wedge-nosed airplane will “cut” through the air easier than the blunt-nosed airplane. This is just like the knife and the ruler, except you are using air instead of clay.
FORMATIVE EVALUATION: Students will be evaluated on the completion of StudentActivity Sheet 5.
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Name _______________________________________
Activity #5: The Wedge
MATERIALS: 2 pieces of paper, scissors
PROCEDURE:
1. Make 2 identical paper airplanes.2. Cut the nose off of one. Leave the other alone.3. Each person in your group should have a chance to fly the planes. Take turns throwing
each plane. Measure the distance in meters each one flew and write it in the chart in the column “Distance Plane Flew”.
4. Which plane flew the farthest the 2 times you flew it?
5. Explain why the plane that flew the farthest did so.
6. Write the definition of a wedge:
PLANEDISTANCE PLANE FLEW
TRIAL #1DISTANCE PLANE FLEW
TRIAL #2
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ACTIVITY #6: Screws
TIME: 45 Minutes
OBJECTIVES: Students will learn that a screw is actually an inclined plane wrapped around a post. They will learn the advantages and disadvantages of wide thread screws and narrow thread screws.
TEACHER BACKGROUND INFORMATION: A screw is actually an inclined plane that has been wound around in a spiral. The thread of a screw refers to the ridges that protrude along its length. A narrow thread screw has the ridges close together, whereas a wide thread screw has the ridges farther apart. The steeper the inclined plane from which the screw was made, the wider the thread. The more gradual the inclined plane from which the screw was made, the narrower the thread. For every turn of the screwdriver, the screw will go into the wood as far as its threads are apart.
Examples of screws in our everyday lives are spiral staircases, roads around mountains, screw type jacks, and clamps.
When doing this activity, you need to hammer the screws into the wood a tiny amount so that the students will be able to screw them in without the screws toppling over. It is best in this activity to work through the steps as a class, recording information on the sheets together when appropriate.
MATERIALS: 10 blocks of balsa wood 10 narrow thread screws 10 wide thread screws 10 screwdrivers
TEACHER/STUDENT PROVIDED MATERIALS: Markers or crayons Scissors Tape 2 pencils each
PROCEDURE:
1. Have students look at the two inclined planes pictured on Student Activity Sheet 6. Discuss which one they would climb if they wanted to use the least effort (or force), and which one they would climb if they wanted to walk the shortest distance.
2. Have them color along the slanted edge of the four inclined planes, two on sheet 6A and two on sheet 6B. Both steep ones should be colored one color, and both gradual ones should be colored one color. They should cut out the larger of each plane. Place the vertical edge of the triangle along the length of the pencil, and wrap it around the pencil and fasten it with tape. Do the same with the other one.
3. Have students compare these models to the wide and narrow thread screws. Which one does the model screw made from the steep incline look like? Which one does the model screw made from the gradual incline look like?
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4. Tell students they will try screwing each one into a piece of wood and that they will measure how far in each will go. Make sure students know how to measure the height of the screw sticking above the wood before they start and how to measure the height when they are finished They also need to make sure they give each screw the same number of turns. A turn will be considered when the groove for the screwdriver returns to its starting position (a 1/2 rotation).
5. Let students predict which one will take the most and least effort to screw in, and which one will go in the farthest. Give them time to complete the activity and then bring them back for a discussion. Be sure they can relate their results to the pictures of the inclined planes. They should look back at the miniature inclined planes they colored for help.
It takes more force to screw in the wide thread screw, just like more force is required to walk up the inclined plane from which it is made. The wide thread screw will also go in farther on any given turn of the screwdriver, since the inclined plane it is made from is a shorter distance.
Just the opposite is true for the narrow thread screw. Less force is needed to screw it in, since it is made from a more gradual inclined plane. For every given turn of the screwdriver, it will go into the wood less, since the inclined plane it is made from covers a longer distance. The same amount of work would be done in either case: less force is used over a longer distance for the narrow thread screw, while more force is used over a shorter distance for the wide thread screw.
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Name _______________________________________
Activity #6: Screws
MATERIALS: wide thread screw, narrow thread screw, screwdriver, tape, 2 colors of crayons, scissors
PROCEDURE:
1. Look at the inclined planes.2. Which one would you want to walk up if you wanted to use the least amount of force?
3. Which one would you want to walk up if you wanted to go the shortest distance? (Use a ruler if you are not sure)
A. B.
4. On the next page, color both “A” inclined planes one color along the edge. Color both “B” inclined planes another color along the edge.
5. Cut out the large “A” and “B” inclined planes.6. Wrap each inclined plane around a pencil and tape the edge.
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color here
color here
colo
r her
e
colo
r her
e
Wra
p ar
ound
penc
il an
d ta
pe
A.
A. B.
B.
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SIMPLE MACHINES
7. Which screw does inclined plane “A” look like?
8. Which screw does inclined plane “B” look like?
9. Predict which screw will take the most effort to screw into a block of wood.
10. You will turn each screw 9 times. Predict which screw will go in the farthest.
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Now you are ready to test your guess.
11. Use a metric ruler to measure (in millimeters) the height of the screw you can see above the wood. Record that for each screw in the chart under “Height Before”.
12. Each group member will turn the screwdriver 3 times. A turn is when the notch on the head of the screw returns to its starting position.
13. Turn the screws. Measure the height of the screws above the wood and record it in the chart under “Height After”.
14. Subtract the first measurement from the second measurement (“Before” from “After”). Write that number in the column “Amount Screw Went In”.
15. Which went in the farthest?
16. Which took the most force (or effort)?
17. Look back at the inclined planes you colored.
Remember which took the most force?
Remember which you could go up in the shortest distance?
Explain the results of the screws.
The ____________________ screw took the most force to screw in because:
The ____________________ screw went in the farthest because:
ScrewHeight of
Screw BeforeHeight of
Screw AfterAmount Screw
Went In
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SIMPLE MACHINES
ACTIVITY #7: Levers
TIME: Two 40 minute periods - Day 1, steps 1-4; Day 2, steps 5-14
OBJECTIVE: Students will observe and use levers of various types. They will learn correct placement of the fulcrum so that more or less effort is needed to lift the load.
TEACHER BACKGROUND INFORMATION: Please take a few moments to read the Simple Machines Background Information at the beginning of this guide if you have not done so already. There are 3 classes of levers - first, second, and third. First class levers let you apply more force or give you more distance and speed. (Seesaws and crowbars are examples. Scissors and pliers are two first class levers put together.) Second class levers let you apply more force only. (They usually work with a tilting motion. Wheelbarrows and bottle openers are examples.) Third class levers increase the speed or the distance of your applied force. (These usually work with a swinging motion. A baseball bat, golf club, broom, and fly swatter are examples.) The students will not be required to differentiate among the three, but rather will learn to recognize items as levers.
MATERIALS (per group of 5 students): 2 wooden rulers 2 pencils 10 washers Per student: Paper lunch bag Tongue depressor Bingo chip Screwdriver Piece of wood TEACHER PROVIDED MATERIALS FOR EXTENSIONS: Bottle opener Pizza cutter Nutcracker Hammer Nail Quick or paint can with lid Scissors Paper punch Paper cutter 2 baseball bats Broom, rake, or fishing pole Pliers
PROCEDURE:
1. To introduce levers, mention either or both of these examples that students should be familiar with. Students should have seen the Road Runner/Wiley Coyote cartoons in which the coyote uses a stick and rock to push a huge boulder over the cliff to land on the Road Runner. Or, mention the playground seesaw.
2. To become familiar with the terms used when discussing levers, students will begin with first class levers. Pair students in groups of five. Each group needs 2 wooden rulers, 2 pencils, and 10 washers. Have them assemble the items like a seesaw, with the ruler resting on the pencil. Use the terms in the vocabulary list in the manual to discuss load, effort, and fulcrum.
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SIMPLE MACHINES
- The fulcrum (pencil) is the point on which a lever is supported so it can swing, tilt, or balance.
- Effort is the force applied to a machine. This can be a washer or a push with your finger.
- Load is the object to be moved. Use any of the remaining washers.
3. Have students do the activities on Student Activity Sheet 7. Bring the class back together to discuss the results. Students should conclude that:- less force is necessary to lift a load when the fulcrum is close to the load. More force is necessary to lift a load when the fulcrum is far away from the load.
- the load cannot be raised as high when the fulcrum is close to the load. The load can be raised higher when the fulcrum is far away from the load.
4. Pass out the paper bags. Let each student make a face on the bag. The top will be rolled down a few inches, so they should not draw all the way to the top. This “monster” needs to be fed bingo chips using a tongue depressor and pencil. Have students predict where they would place the fulcrum to be able to get the chip in the bag. Let the students experiment positioning the tongue depressor and the pencil and flipping the chips. When everyone has finished, discuss that the fulcrum had to be farther away from the load to attain the desired lift that propelled the chip into the bag. Leave the chips, bags, and tongue depressors in the back of the room for students to see who can get the most chips in the bag.
FORMATIVE EVALUATION: Students will be evaluated on the completion of Student Activity Sheet 7.
PROCEDURE:
1. If you feel the students would understand the classes of levers, you may introduce them using the diagrams at the end of this section. As you discuss each class, point out its purpose: force, speed or distance, or both. Otherwise, simply mention that levers come in different forms and can help us apply more force, increase the speed or distance that the load moves, or both.
2. Start with the more obvious first class levers. Use the screwdriver to pry off the lid of a can of the Quick or the lid of a paint can. In the case of this first class lever, you want to apply force. By pushing down, the lid will come up. You may want to draw a picture and label the effort, the load, and the fulcrum.
3. Hammer a nail into a piece of wood before class. Use the hammer to pull it out. This is used as a first class lever. As you apply force downward, the flat nose of the hammer works as a fulcrum and the split end with the nail is the load to be lifted up. Again, you may wish to draw and label the parts.
4. Spread scissors apart and show the students that this is two levers put together. The finger hole is the effort, the point where they are joined is the fulcrum, and the blades are the load. This is easy to see when each blade and handle is focused upon separately.
5. A pair of pliers or a paper punch are other examples similar to the scissors.6. Demonstrate the second class levers. These let you apply an increased force and usually
work with a tilting motion. Start with a bottle opener, showing that the lifting motion is the effort, the sharp end (or round open part, depending on how you are using it) is the fulcrum, and in between your hand and the sharp end is the load. Again, draw simple sketches to show the various parts.
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7. Demonstrate a pizza cutter. The end you hold is the effort, the fulcrum is the wheel, and the load is in between your hand and the wheel.
8. A wheelbarrow is another example. A nutcracker is 2 second class levers put together, giving you increased force at the fulcrum, where the 2 arms are joined. Again, where you position your hands is the effort and the load is in between here and the place the arms are joined.
9. A paper cutter is also a second class lever. The effort is where you hold the cutting arm, the fulcrum is where the arm joins the base, and the load is the part in between where the paper is cut.
10. Demonstrate third class levers. These work with a swing and give speed or distance as a trade-off for force. An example is a baseball bat. The fulcrum is the narrow end of the bat, the effort is where you hold it, and the load is the fatter end that hits the ball. The same applies for a broom, a rake, a golf club, a fishing pole, a hammer (when you are nailing), and even a swing. In the latter case, the fulcrum is where the swing is attached to the swing set, the effort is where you hold the chain, and the load is the seat or seated person. Be sure to discuss the examples even if you do not have them to demonstrate. As always, sketches with the labeled parts are helpful for visualization by the students.
11. Leave the various levers in a learning center for the students to experiment with.12. Can a child lift an adult? Place a 2 x 6 6 foot board on a braced fulcrum and have the
teacher stand on one end and a child at the other. Can students figure out what must be done to achieve this feat? For visual effect, make signs that say “Effort” and “Load” and have the people on the board wear the appropriate signs. Be sure to discuss the positioning of the fulcrum each time.
spotter
spotter
spotter
2 x 42 x 4 2 x 4
2 x 4 scraps for brace
nail bracepieces from top
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SIMPLE MACHINES
Name _______________________________________
Activity #7: Levers
MATERIALS PER GROUP OF 5: 2 wooden rulers, 2 pencils, 10 washers
PROCEDURE:
1. Place each ruler (lever) on a pencil (fulcrum).2. Place 2 washers on the l centimeter end of each ruler.3. Move the fulcrum to the 8 centimeter mark. Record on the next page how many washers
it takes to lift the load.4. Move the fulcrum to the 14 centimeter mark on the ruler. Record on the next page how
many washers it takes to lift the load.5. Move the fulcrum to the 20 centimeter mark on the ruler. Record on the next page how
many washers it takes to lift the load.6. Move the fulcrum to the 23 centimeter mark on the ruler. Record on the next page how
many washers it takes to lift the load. Answer question #10 below.7. Now, place one ruler on a pencil at the 8 centimeter mark. Place the other ruler on the
pencil at the 20 centimeter mark. Line the rulers up with each other so that they are even.8. Place 2 washers on each ruler at the 1 centimeter mark. Place as many washers as needed
to lift the load for each one.9. Compare the height the load moved on each ruler. Answer question #11 below.
Underline the correct word in parentheses.
10. If the fulcrum is close to the load, it takes (more, less) force to lift the load than if the fulcrum is far away.
11. If the fulcrum is close to the load, the load moves (higher, lower) than when the fulcrum is far away.
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ACTIVITY #8: The Wheel And Axle
TIME: 35 Minutes
OBJECTIVE: Students will construct a simple wheel and axle. They will see that turning the axle gives increased distance at the wheel, while turning the wheel provides increased force at the axle.
TEACHER BACKGROUND INFORMATION: A wheel and axle must be firmly fixed together to be considered a true simple machine. When the wheel spins, so does the axle. When the axle spins, so does the wheel. An automobile has a true wheel and axle combination. A windlass (think of a well from which water is drawn by turning a wheel and axle to which a bucket is attached) is a true wheel and axle combination.
Some things appear to be wheel and axles when they are not. On some vehicles, the wheels’ only purpose is to reduce friction by lessening the surface area that comes into contact with the road. Its axles do not move. Thus, spinning the axle would not cause the wheels to move and vice versa.
For every turn of the axle, the wheel turns a greater distance. This comes in handy when we want to get in our cars and travel any distance! Turning the wheel, on the other hand, makes it easier to exert force. Think of how difficult it would be to turn the axle of a windlass if we wanted to draw water from a well. Or, think of a homemade ice cream machine. Imagine not being able to turn the crank handle but instead having to turn the axle. The same is true of a hand-held egg beater.
Students will need to save their milk carton from lunch before this activity can be done.
MATERIALS: String Student Activity Sheet 8A and 8B Hand-held egg beater Masking tape Paper clip (per student) Pencil (per student)
TEACHER/STUDENT PROVIDED MATERIALS: Construction paper circles (2 per student) Paper punch Pencil Scissors 2-3 books Crank-type pencil sharpener Milk carton for each student
PROCEDURE:
1. The best way to introduce this lesson is to have children build a wheel and axle. Go through the definition of a wheel and axle (a wheel that turns a post).
2. Pass out the circle patterns that have already been run off on construction paper. These should be cut out and a hole punched in the center with a paper punch. Instruct students to slip their pencil through each wheel. (As an alternative, you may wish to have students use their own compass to draw a circle with a specified diameter, then follow the same procedure.)
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3. Hand out Student Activity Sheet 8A, and allow students to complete the activity. Discuss the results, noting that although one complete revolution of the axle produces one complete revolution of the wheel, having the wheel on the axle results in greater distance being covered than would be possible with the axle alone.
4. Pass out Student Activity Sheet 8B and let students construct a windlass (or wheel and axle). Discuss how much easier it was to turn the paper clip (the wheel) instead of the pencil (the axle).
5. Demonstrate how a wheel and axle makes work easier. Tie 2-3 books Christmas-present style with string. Allow students to lift the weight of the books by pulling the string with their hands. Next, take the cover off a pencil sharpener, and tie the string very tightly to the protruding shaft of the pencil sharpener. If the yarn is not tied tightly, it will slip off when the shaft is rotating. You may even wish to tape the string to the shaft. Let students turn the handle of the pencil sharpener to lift the books. Do they notice a difference in the force they needed to lift the books with their hands as opposed to using the pencil sharpener?
6. As a final demonstration, let one or more students see how difficult it is to turn a hand-held egg beater by moving the axle as opposed to turning the handle. NOTE: Caution children to keep their fingers above the beaters and below the handle when turning at the axle.
FORMATIVE EVALUATION: Students will be evaluated on the completion of Student Activity Sheets 8A and 8B.
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Name _______________________________________
Activity #8a: The Wheel And Axle
MATERIALS: 2 construction paper circles, paper punch, pencil, pen
PROCEDURE:
1. Cut out the circles and punch a hole with the paper punch in the center of the circle.
2. Make a mark with your pen near the edge of one of the circles.
3. Slip both circles onto your pencil and spread them apart.
4. Line the mark on the circle up with the writing on the pencil.
5. You have just made a model of a wheel and axle.
6. Place your wheel and axle on the starting line on the next page so that the marks you have made on the wheel are even with the starting line.
7. Roll the wheel and axle until the mark on the wheel and axle return to their starting position. Make a mark on your paper to show this distance. Write “wheel and axle” by this mark.
8. Take the wheels off the axle. Roll the axle from the starting line until the writing on the pencil returns to its starting position. Make a mark on your paper to show this distance. Write “axle alone” by this mark.
9. Did the axle move as far as it did when the wheels were attached? _
10. Write the definition of a wheel and axle:
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STARTING LINE
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Name _______________________________________
Activity #8b: The Wheel And Axle
MATERIALS: paper clip, pencil, string, milk carton, tape, soufflé cup, scissors, paper punch, 2 washers
PROCEDURE:
1. Open the outer ring of the paper clip so that the clip forms a “Z” shape.
2. Use masking tape to hold the paper clip to one end of the pencil.
3. Cut two pieces of string, each about the height of the milk carton.
4. Make a tiny hole on each side of the soufflé cup and thread each string through a hole. Knot the ends so the string won’t slip through.
5. Cut the top off the milk carton. Punch a hole on either side of the carton and slide your pencil through the holes.
6. Place the soufflé cup in the carton and tape each string to the pencil.
7. Place the 2 washers in the soufflé cup. Turn the paper clip handle to raise the soufflé cup of washers.
8. Now, turn the pencil to raise the soufflé cup of washers.
9. Which was easier - turning the paper clip or turning the pencil?
10. Which is the wheel- the paper clip or the pencil?
11. Which is the axle - the paper clip or the pencil?
tape to
pencil
paper clip
tape
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ACTIVITY #9: Wheels With Teeth - Gears
TIME: 30 Minutes
OBJECTIVE: Students will see that wheels with teeth are gears. They will study the effect a larger gear has on a smaller gear. They will see how gears can change the direction of moving parts in a machine. They will understand how gears are used in an eggbeater.
TEACHER BACKGROUND INFORMATION: Wheel and axle combinations may be modified to interact with one another by using toothlike projections on the circumference of the wheel to form gears. A hand-held egg beater is an example of a double wheel and axle where the wheel (handle) has a large gear on the axle. The large gear acts as a wheel to turn the 2 smaller gears on the axle (thin post with beaters). The large gear causes the smaller gears to turn many more times and thus the beaters turn quite rapidly.
This activity is done in stations. If possible, you may wish to have students bring in extra hand held egg beaters to facilitate work at the stations.
MATERIALS: Georello gear set Hand-held egg beater Masking tape
PROCEDURE: Set up the stations listed below. Student instructions for each station are listed on Student Activity Sheet 9.
Station 1 - You should be able to set up 2 stations by using 2 medium gears and 2 small gears as the samples. Place two gears of the same size from the Georello gear set on the interlocking plate. The gears should be side by side, interlocking. Place the colored knobs in one of the teeth on each gear. These are the teeth students should line up with each other when beginning the activity. Use masking tape to label the one on the left “Gear 1”, and the one on the right “Gear 2”.
Station 2 - Using the Georello gear set again, place a medium gear on the left side and a small gear on the right side of the interlocking plate. Make another set with a large gear and a small gear. Again, you should be able to set up two stations. The gears should be side by side, interlocking, and the teeth marked with colored knobs. Use masking tape to label the one on the left “Gear 3” and the one on the right “Gear 4”.
Station 3 - Use masking tape to mark one blade of the hand-held egg beater.
FORMATIVE EVALUATION: Students will be evaluated on the completion of StudentActivity Sheet 9.
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Name _______________________________________
Activity #9: Gears
PROCEDURE: Visit each station your teacher has set up. Answer the questions for each station.
STATION 1:
1. Line up the teeth of the gears so that the colored knobs on the teeth interlock. Turn Gear 1 clockwise. This means to turn it the same direction the hands on the clock move. Circle which way Gear 2 moves.
2. How many times did Gear 2 turn before the colored knob on the tooth lined up with the colored knob on Gear 1?
3. For every turn of the same sized gear, does the second gear turn around
less times the same number of times more times
STATION 2:
1. Make sure the teeth with colored knobs are interlocked.
2. Have your partner watch how many times Gear 4 turns. He or she should watch for the tooth with the colored knob to return to its starting position. Slowly move Gear 3 clockwise (this means to move it in the same direction the hands on a clock move). Keep moving it until you see the knob on the tooth of the gear return to its starting position. Tell your partner to stop counting once this happens.
3. How many times did the small gear (#4) turn?
4. For every turn of a larger gear, a smaller gear turns
more times fewer times
Gear 1Gear 2
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STATION 3:
1. Turn the handle. As the large gear turns, what happens to the 2 small gears?
2. As the small gears turn, what happens to the post with the beaters?
3. Turn the handle once. Count how many times the masking tape on the beater returns to its starting position. Write that number on the line below.
4. How does the large gear on the handle make the beaters easier to turn?
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ACTIVITY #10: Pulleys
TIME: 35 Minutes
OBJECTIVE: Students will learn how pulleys can make work easier by changing the direction of force or reducing the amount of force that must be applied.
TEACHER BACKGROUND INFORMATION: The purpose of a single pulley is only to change the direction of force. In other words, it can allow lifting to be done by pulling downward. It does not reduce the amount of force that must be applied to lift the load. A double pulley, on the other hand, reduces the amount of force necessary to lift the load. However, you have to apply this force over a greater distance. This might mean that to lift something 1 meter, you have to pull the rope down 2 meters.
MATERIALS: 2 dowel rods Spring scale 2 single pulleys Pulley cord
TEACHER PROVIDED MATERIALS: rope or clothesline
PROCEDURE:
1. Introduce pulleys by taking students outside to the flagpole. Discuss how difficult it would be to climb the flagpole every morning and afternoon to raise and lower the flag. Show students how the flag is raised and lowered. A pull on one side of the rope raises the flag. If the rope is released, the flag lowers. The pulley (a grooved wheel with a rope around it) at the top of the flagpole allows this to be done.
2. Tell students that a single pulley only changes the direction of force, while a double pulley actually reduces the force. Set up a single pulley according to the diagram at the end of this section. Tie several books to one end of the rope. Tie the spring scale to the other side and pull gently to measure the force required to lift the books to a certain height. Have students write this number down.Now assemble a double pulley according to the directions at the end of this section and lift the books again. Measure the force required to lift the books to the same height as before. Students should record this number and see that it is less than with the single pulley. If you think they understand the concept of Force x Distance, explain that although you used less force with a double pulley, you had to use more rope or distance to lift the books.
3. Try this “contest of strength”. Using the dowel rods in the kit, tie a piece of rope tightly to one of the dowel rods, about a third of the way down. Have one student hold this rod vertically to the ground with both hands above and below the rope. Have another student hold the other dowel rod. Wind the rope back and forth between the two dowel rods. Have another student pull on the free end of the rope to move the rods together, while the original two students pull to move the dowel rods apart. The person using the rope should win every time, since this is a multiple pulley. CAUTION: The rope must be tied securely or it may come loose. It is also advised to have students sitting or kneeling during this activity.
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CULMINATING ACTIVITY: Identifying Simple Machines
TIME: One class period
OBJECTIVE: Students will identify simple machines.
MATERIALS: Simple machines brought from home by the students Student Response Chart
PROCEDURE:
1. Have students bring examples of simple machines from home. A good rule is that the machines should fit into a brown paper bag.
2. Look over the simple machines brought in. Set out examples of the simple machines for students to identify on their response charts. If you wish to assign a grade, points can be given for the machines brought in as well as for correct identification.
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Name _______________________________________
For each simple machine, put a check mark under the correct identification.
PULLEY LEVER SCREW WEDGE WHEELINCLINED
PLANE1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
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Glossary
axle the post on which a wheel turns
cog a tooth on a gear wheel
effort force that is applied to a machine to produce an action
force push or pull
friction force that slows down or stops motion
fulcrum the point on which a lever is supported so that it can balance, tilt, or swing
gear a wheel with teeth
load the object moved by a lever
machine anything that makes work easier
simple machine a machine with few or no moving parts
thread the groove around a screw or inside a nut
work what is done when a push or a pull moves something
THE 6 SIMPLE MACHINES
inclined plane a sloping surface that goes from a lower to a higher level
lever a bar or rod that turns on a point (the fulcrum)
pulley a wheel over which a rope, chain, or belt passes
screw an inclined plane wound around in a spiral
wedge two inclined planes joined back to back to form a sharp edge
wheel and axle a wheel that turns a post
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ACTIVITIES REQUIRING ITEMS THAT ARE NOT FOUND IN THE CLASSROOM
Activity 1: a stick or dowel rod per pair of students, a plastic pinwheel
Activity 2: two lightweight items per student
Activity 3: two lightweight items per student
Activity 4: two lightweight items per student
Activity 7: chocolate milk drink mix (Quick) can or paint can with lid, any 2 of a baseball bat, broom, rake, fishing pole
Activity 8: one milk carton per student from lunch
