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Energy

Teacher andAmbassador Guide

Science Starts With a Question

Science Starts With a Question: Energy i

Science Starts With a Question is a collaboration between the Smithsonian Science Education Center and The Dow Chemical Company.

About the Smithsonian InstitutionThe Smithsonian Institution was created by an Act of Congress in 1846 “for the increase and diffusion of knowledge…” This independent federal establishment is the world’s largest museum and research complex and is responsible for public and scholarly activities, exhibitions, and research projects nationwide and overseas. Among the objectives of the Smithsonian is the application of its unique resources to enhance elementary and secondary education.

About the Smithsonian Science Education Center The Smithsonian Science Education Center (SSEC) is operated by the Smithsonian Institution to improve the teaching of science in the nation’s schools. The SSEC disseminates information about exemplary teaching resources, develops curriculum materials, and conducts outreach programs of leadership development and technical assistance to help school districts implement inquiry-centered science programs. Its mission is to transform the teaching and learning of science in a world of unprecedented scientific and technological change.

Smithsonian Science Education Center staff involved in development of this publication

Brian Mandell, PhD Curriculum Developer

Katya Vines, PhD Curriculum Developer Claudia Campbell, Jean Flanagan, Patti Marohn Editors

Ashley Deese Designer

Elizabeth Klemick Brannan Proofreader

Taryn White Production Specialist

Marjee Chmiel, PhD Associate Director for Curriculum and Communications

Amy D’Amico, PhD Director of Professional Services

Eric Nastasi, Esq. Senior Advancement Officer

Lisa Rogers Director of Finance

Teng Chamchumrus Interim Director Teachers involved in development of this publication

David Brown Science TeacherBullock Creek Middle School, Michigan

Scott Harrison Science TeacherFreeland Elementary School, Michigan

Science Starts With a Question: Energy ii

About The Dow Chemical CompanyDow’s STEM mission is to build the workforce of tomorrow by empowering teachers, motivating student achievement, developing careers, and collaborating with communities to transform STEM education into a driver for innovation, manufacturing, and economic prosperity.

To live out this mission, Dow has created STEMtheGAP™—a growing and constantly evolving series of initiatives to support and advance STEM education. While stakeholders, target audiences, and focuses may vary, every initiative is designed to inspire conversation about STEM education, collaboration to develop innovative solutions and, as a result, transformation that will enable our nation and the world to surmount the challenges of the 21st century.

For more information on Dow’s STEMtheGAP™ initiatives, visit: http://www.dow.com/company/citizenship/stem.htm

Dow staff involved in development of this publicationMegan Frager Mechanical Engineer

Michael Lowe, PhD Chemist

Andrew Pasztor, PhD Retired Chemist

Michael Switala Electrical Engineer

Tricia Wilson Chemical Technologist

Jaime Curtis-Fisk, PhD Chemist

Evaluation of the safety of chemicals used in this moduleA Safety Data Sheet (SDS) is the main document scientists at Dow use to assess the safety of chemicals. The SDS lists any hazards associated with the chemical, including potential hazards such as what might happen if the chemical is dropped or if it comes into contact with air or water. Before carrying out an activity, a Dow scientist refers to the SDS for every chemical he or she is going to use. This allows the scientist to decide what personal protective equipment to wear and where to carry out the reaction. Dow uses a color-coding system for every chemical. All of the chemicals in this module belong to the green category, which is the category associated with the lowest level of risk. Dow recommends and includes appropriate safety precau-tions in the Stay Safe boxes in both the Teacher Guide and Student Guide.

©2015 Smithsonian Institution

Image CreditsMarble Dash Setup - The Dow Chemical Company; Teacup Stirling Engine - The Dow Chemical Company

The illustrations on the cover and chapter opening page are by Tim Bradford.

Science Starts With a Question: Energy iii

How to Use This Guide

Welcome to your Energy Teacher Guide! This Guide contains all the information you need to teach the Energy module produced by the Smithsonian in partnership with The Dow Chemical Company. You will also find background information on all the activities and links to the Next Generation Science Standards and the Michigan Performance Standards.

The following features in this Guide will help you teach this module:

Stay Safe

Take opportunities to relate what the students are doing to what the ambassador scientist does.

Science is fun but can also be dangerous. Emphasize safety advice to your students.

What Scientists Do

Science Starts With a Question: Energy 1

Science Starts with a Question:

Energy

Module OverviewStudents will be participating in a series of activities based on a model-based inquiry framework that explore:

Different types of energy, Energy transformations, and The concept of energy transfer.

Students will develop a model of an observed phenomenon. Then they will explore their model by carrying out a series of activities. Finally, they will use evidence from their experiences to evaluate and refine their model. They will also use the model to test a prediction. Scientists from Dow Chemical will help students connect what they do in the classroom to what they may do in a STEM career.

Lesson Activity Length Teaching StyleLesson 1: Model Development

Marble track 40 minutes Teacher demonstration and teacher-guided student activity

Lesson 2: Model Investigation

A series of activities demonstrating the different types of energy, energy transformations, and energy transfer

40 minutes Ambassador demonstrations and ambassador-guided student activities

Lesson 3: Model Evaluation

Marble track 40 minutes Teacher demonstration


Module Level Performance Expectations These expectations are based on the Next Generation Science Standards (NGSS) performance expectations for this module. They combine core ideas, practices, and crosscutting concepts.

At the end of this module, students will be able to:

Construct an argument that a system is a set of interrelated parts that make up a unified whole. Analyze and interpret data to determine the six ways energy can be stored in systems. Apply an understanding of how energy can transform from one type of energy into

another within the same system. Use a model to conceptualize how energy can transform from one form into another. Use evidence to explain the three ways energy can transfer between systems.

Central QuestionWhere does the energy we use come from?

NGSS AlignmentThe NGSS framework combines disciplinary core ideas, crosscutting concepts, and science and engineering practices. NGSS performance expectations integrate these three elements. NGSS is designed to be flexible so that teachers can include additional science and engineering practices in their instruction. Students will work toward the performance expectations listed in this module but will not be expected to achieve them fully until the end of grade 8.


Performance ExpectationsMS-PS3-5 Construct, use, and present arguments to support the claim that when the kinetic energy of an object changes, energy is transferred to or from the object.

In Lessons 1–3, students observe a number of activities where energy transfers to or from an object. Students will incorporate these observations into arguments that explain how energy can be stored and transferred.

Science and Engineering PracticesFocus practices

Developing and using modelsDevelop and/or use a model to predict and/or describe phenomena.

In Lesson 1, students develop a model to explain the energy used as a marble makes its way down a ramp. They use the model to make a prediction, which will be tested in Lesson 3.

Develop or modify a model – based on evidence – to match what happens if a variable or component of a system is changed.

In Lessons 1 and 3, students develop, investigate, and revise a model to show the transfer of energy from potential to kinetic energy on a marble track.

Engaging in argument from evidenceConstruct, use, and present oral and written arguments supported by empirical evidence and scientific reasoning to support or refute an explanation or a model for a phenomenon.

In Lesson 1, students construct an argument of the mechanics of energy transfer and use evidence to defend their model in Lesson 3.

Additional practices

Planning and carrying out investigationsCollect data to produce data to serve as the basis for evidence to answer scientific questions or test design solutions under a range of conditions.

In Lesson 2, students collect quantitative data as evidence of energy transfer and energy transformations.


Analyzing and interpreting dataAnalyze and interpret data to determine similarities and differences in findings.

In Lesson 2, students compare similarities and differences in quantitative and qualitative data. These data help them determine the type of energy transfer observed in the activity.

Constructing explanations and designing solutionsConstruct an explanation using models or representations.

Using a model developed in Lesson 1, students explain their observations of energy transformations.

Disciplinary Core IdeasPS3.A: Definitions of energyA system of objects may also contain stored (potential) energy, depending on their relative positions.

Lessons 1–3 expose students to the nature of systems and stored energy.

PS3.B: Conservation of energy and energy transferWhen the motion energy of an object changes, there is inevitably some other change in energy at the same time.

In Lessons 1–3, students observe a variety of situations where a change in one part of the system affects the system as a whole.

Energy is spontaneously transferred out of hotter regions or objects and into colder ones.

In Lesson 2, students relate energy transfer to temperature changes.

PS3.C: Relationship between energy and forcesWhen two objects interact, each one exerts a force on the other that can cause energy to be transferred to or from the object.

In Lesson 2, students observe two objects interacting and the energy transfer that takes place.


Crosscutting ConceptsEnergy and matterEnergy may take different forms (e.g. energy in fields, thermal energy, and energy of motion).

Lesson 2 presents students with six activities that ask them to identify the different ways energy is stored in systems.

Influence of science, engineering and technology on society and the natural world Modern civilization depends on major technological systems. Engineers continuously modify these technological systems by applying scientific knowledge and engineering design practices to increase benefits while decreasing costs and risks.

Students will explore and discuss the practical implications and impact of human-generated energy in the Extending Your Knowledge section.

Michigan Department of Education Science Standard Alignment

Performance StandardsP.EN.06.11 Identify kinetic or potential energy in everyday situations (for example: stretched rubber band, objects in motion, ball on a hill, food energy). In Lessons 1 and 2, students identify the differences between kinetic and potential energy.

P.EN.06.12 Demonstrate the transformation between potential and kinetic energy in simple mechanical systems (for example: roller coasters, pendulums).

Lessons 1 and 3 present students with a Marble Dash activity that demonstrates the energy transformation from potential energy to kinetic energy within a system.


P.EN.06.41 Explain how different forms of energy can be transferred from one place to another by radiation, conduction, or convection.

Each activity in Lesson 2 is specifically designed to present the three ways energy can transfer from one system to another.

P.EN.07.33 Demonstrate how waves transfer energy when they interact with matter. In a series of activities in Lesson 2, students explore how waves transfer energy.

Pre-requisite Knowledge and Skills Before starting this module, students should know:

Energy is something that changes. When objects are put in the oven, they absorb energy (Michigan: P.EN.E.04). When objects are put in a freezer, they lose energy.

Energy is something quantifiable. For example, objects like an aircraft carrier moving through the water at 20 knots, have an incredibly large amount of energy. Objects like a fruit fly sitting on an apple have very little energy.

Energy released from food was once energy from the sun that was captured by plants in a chemical process that forms plant matter (NGSS: 5-PS3-1).

Before starting this module, students should be able to:

Use models to describe phenomena. Support an argument with evidence, data, or a model. Use evidence to construct an explanation.

Module Background Information This information goes beyond what is expected of students, but will help the teacher effectively use the module and respond to student questions.

Energy and matter make up everything in the universe. Matter is anything that has mass, and energy is the ability to do work or cause change. Energy can cause things to change on large scales, like collapsing stars, and on small scales, like moving electrons around a nucleus. One of the ways scientists conceptualize energy is by looking at systems.

Systems are a combination of things or parts that work together as a unit. A good example is our circulatory system. This system moves nutrients, oxygen, and water throughout


our bodies. It is made up of our heart, arteries, veins, blood, and many other parts that work together as a unit. Systems also can be used to represent batteries, car engines, and generators. They help us understand energy transformations and energy transfers within these systems.

This module will explore:

The different ways energy can be stored, How it can change within a system, and What changes when energy transfers from one system to another.

Types of EnergyThere are two states of energy: kinetic and potential. Kinetic energy is the energy of motion. Potential energy is stored energy. Energy comes in six forms that represent the different ways energy can be stored in a system. The six forms of energy are radiant, thermal, electrical, mechanical, nuclear, and chemical.

Radiant energy is kinetic energy. It is the energy of electromagnetic radiation that travels in transverse waves. Radiant energy includes visible light, x-rays, gamma rays, and radio waves.

Thermal energy is kinetic energy. It is more commonly known as heat. Thermal energy is the total energy of the moving atoms and molecules in a substance. As substances heat up, the atoms and molecules within it move faster.

Electrical energy is kinetic energy. It is the movement of charged particles called electrons.

Mechanical energy can be either kinetic energy or potential energy. When an object is in motion, like a train moving down the track, it has kinetic energy. When that same object is at rest on the top of a hill, it has potential energy.

Nuclear energy can be either kinetic energy or potential energy. An atom can split through a process called fission or fuse with another atom through a process of fusion. These processes release large amounts of energy. This is an example of kinetic energy because particles and energy are moving. The energy holding the atom together is considered potential energy because it is stored energy

Chemical energy is potential energy. It is the energy stored in the bonds of an atom, a molecule, or a compound.


Energy TransformationsEnergy transformation is the process of changing one form of energy into another within a system. Energy cannot be created or destroyed, under normal circumstances, but can always be transformed in a system. Scientists call this the law of conservation of energy.

Energy flow diagrams are one way to visualize how energy transformations can occur within a system. These diagrams show, in a sequential format, the energy source and the energy output. For example, a toaster’s energy source would be electrical energy and the energy output would be thermal energy. In some cases, the transformation can generate multiple energy outputs. When electrical energy is used to power a light bulb, both radiant energy and thermal energy are produced.

Energy TransferEnergy can move between systems through a process called energy transfer. The three basic ways energy can transfer between systems are conduction, convection, and radiation.

Conduction occurs when energy transfers from one system to another by direct contact. An example of conduction is cooking pancakes on a griddle. The pancake batter is in direct contact with the hot griddle.

Convection occurs when energy transfers between two systems through the movement of fluids, like air and water. An example of convection would be using a hair dryer to dry your hair. The hair dryer is an excellent example of convection because the hair dryer heats up and pushes air, a fluid, towards your hair.

Radiation occurs when energy transfers between two systems through electromagnetic waves. Radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays, and gamma rays are all examples of electromagnetic waves. It is important to note that radiation does not require travel through any type of matter. This means the transfer of energy through radiation can occur in space. The Sun transferring energy to Earth through space is one example of radiation.

Electrical Energy

Thermal Energy and

Radiant Energy


MisconceptionsThere are common misconceptions that students of this grade have about energy. Research has shown that unless these misconceptions are corrected, students will not fully understand new concepts. It is important to identify and correct student misconceptions using evidence from the activities.

Misconception CorrectionAn object at rest has no energy. Objects at rest, like the marble, have the

potential to move; therefore, they have potential energy.

Only living things have energy. The hand warmer, blocks, and teacup Stirling engine were all non-living things that had an energy source.

Energy is a substance. Several activities in this module show energy transforming within a system or transferring between systems and not occupying space or having mass.

Only hot objects can transfer energy. The cold block conducts heat into an even colder cube of ice.

Teaching Through InquiryIn this module, students answer a central question by collecting evidence from a series of activities. The Student Guide gives the procedures for the activities. However, students have to make decisions on what evidence to collect and how to formulate explanations based on this evidence. The role of the teacher and the ambassador should be to guide students in this inquiry. The teacher and ambassador should avoid giving students answers to questions. Instead, they should direct students to relevant observations and prior scientific knowledge.

A more open inquiry may develop from questions students raise during this module. Teachers may want to collect these questions on a flip chart or Post-it® notes and use them as a basis for a student-designed investigation later.


Lesson 1: Model Development

Lesson OverviewStudents will think about and draw a model of the energy they observe in this demonstration. Their model should show how the energy of the marble changed on its way down the track using arrows, images, and any other symbols. Students will use their model to predict what will happen if certain variables change in the marble track setup. The lesson includes a series of tables focused on energy types, energy transformations, and energy transfer, which students need to complete.

Preparation1. Hand out a copy of the Student Guide to each student.2. Set up the Marble Dash track in the middle of the classroom. Make certain all the marbles will travel the entire length of the track and through the speed sensor (see image below).3. Roll the marble down the track a few times to ensure the speed sensor is working properly.

Let’s Get Started (10 minutes)1. Read the brief overview in the Student Guide together as a class. 2. Have students write down all the words they can think of that have something to do with energy in question 1 of Let’s Get Started in the Student Guide. 3. Prompt students to share what they already know about energy. Student answers will vary, but it is important to be aware of their experience, knowledge, and misconceptions prior to beginning the module. 4. After a class discussion has concluded, transition to the marble track demonstration.


Marble Dash (30 minutes)

Activity Background InformationEnergy transforming from potential to kinetic will be the focus of the marble track demonstration. The motionless marble sitting on the track has stored energy that changes into energy of motion. The observable speed of the marble at the end of the track will help students quantify this process.

Potential energy has two types: gravitational potential energy and elastic potential energy. The subject of the Marble Dash demonstration is gravitational potential energy, which depends on the mass of the object and the height from which the object is rolled. After witnessing the marble being rolled down the track a few times, students will be asked to make a prediction based upon the mass of the marble and the roll height. Students will be asked to predict which scenario, rolling a marble of similar mass from twice the original height, or rolling a marble with twice the mass from the original height, will produce greater speed. While calculating gravitational potential energy involves multiplying the mass, height, and the gravitational field strength, it is more important for students to understand that these variables directly affect the final amount of kinetic energy.

MaterialsFor the teacher1 Projectile ramp2 Marbles (equal size, one with more mass)1 BeeSpi V photogate timer

Procedure1. Make sure all students can see the Marble Dash demonstration. 2. Roll the marble several times down the track from halfway up the incline.3. You may want to write down a few of the speeds on the board for the class.4. Ask students to draw a model showing what happens to the energy of the marble as it makes its way down the track and through the speed sensor for question 1 of What Is Going On.5. After a few moments have passed and you can see that most students have completed their model, have them put their pens and pencils down and listen to one additional instruction.6. Have students make a prediction to answer question 2 of What Is Going On. They should use the space below the scenario they chose to explain their choice. They can use arrows, images, and any other symbols they think will help them explain what might happen. Do not roll a marble from twice the height or one of more mass to test the students’ predictions.


Teaching Notes1. Drawing the model should be an individual activity, although students can discuss their model within their group.

Review1. After students have completed their predictions, have them begin working through the three tables in their Student Guide. These tables will require students to provide examples of different energy types. Students will also identify the energy source and energy output for specific systems. Finally, students will work through different types of energy transfer given certain system combinations.2. Students should understand that there are different energy types, specific energy sources and energy receivers for specific systems, and three different ways energy is transferred between systems. 3. At the end of the lesson, let students know that a scientist from Dow will be visiting for the next lesson. Tell them that they will be using their model to explore the different energy types, specific energy sources and energy outputs for specific systems, and three different ways energy transfers between systems.


Lesson 2: Model Investigation

Lesson OverviewIn this lesson, students will collect evidence that will either support or contradict their model. Students will observe various types and combinations of energy transformations and energy transfers. Students will also make observations, collect evidence, and answer questions that will help them explore their model from Lesson 1.

Experiment title Starting materials Energy transfer Teaching styleStation 1: Student Power

Pedal-powered generator, lamp, photometer

Radiation Ambassador-guided student activity

Station 2A: Hand Warmer

Hand warmer Conduction Ambassador-guided student activity

Station 2B: Chill Out Aluminum block, plywood block, ice cubes, infrared temperature gun, O-rings

Conduction Ambassador-guided student activity

Station 3: Teacup Stirling Engine

Stirling engine, cups, hot water, infrared temperature gun, reflective tape, tachometer, heat-resistant gloves

Convection Ambassador-guided student activity

Station 4A: Radiometer

Radiometer and flashlight


Station 4B: Solar Cell Solar cell, hand crank flashlight, multimeter, and wires



Recommended Roles for Ambassador and Teacher The table below provides suggestions for the role of the ambassador and teacher during this lesson. The ambassador and teacher should discuss this table before the lesson and modify as appropriate to their preferences and needs.

Teacher AmbassadorPreparation Set up classroom for

demonstration and group workPrepare materials for student experiments and put them on workstationsContact ambassadorReview background information

Contact teacher to arrange time and location for set upEnsure all materials are prepared and ready for transportationSet up materials for demonstration

Let’s Get Started Introduce ambassadorLead the Let’s Get Started activityExplain what will happen during the lesson

Explain the role of a Dow STEM ambassadorRemind students of safety rules in the laboratory

Activity Maintain classroom procedures, keep students moving from one station to the next Check in with groups as they work through the stationsAssist students with activities, providing guidance but no answersEnsure students follow safety procedures Ensure students follow clean up and disposal procedures correctly

Check in with groups as they work through the stations. Provide guidance and connections to what you do but no answersVisit all eight groupsEnsure students follow safety procedures Advise students on disposal procedures


Review and return of materials

Make sure all equipment has been returned and put back into their proper locations and containersInform students that additional time will be given to complete questions, energy flow diagrams, and discuss conceptsTransition to ambassador for wrap-up Thank the ambassador for his/her time

Explain what s/he does and relate it to scientific practices that students used in the lessonAddress concepts such as developing and using models, basing ideas on evidence, and confronting misconceptions as time allowsAnswer questions

Preparation 1. Arrange the classroom for students to work in groups of four. There will be eight total groups, divided into two teams. We propose naming one team the Red Team and other the Blue Team. There will be two complete setups for each activity. Note that Station 2 and Station 4 have two parts (A and B). Keep this in mind as you set up the classroom.2. Groups will rotate through the four stations in 7-minute intervals. This will provide time for introductions, safety recommendations, instructions, and time to interview the Dow ambassador as the lesson begins.

Let’s Get Started (5 minutes)1. The teacher should introduce the ambassador (without giving away his/her job title or what he/she does). The ambassador should explain what a Dow STEM ambassador does.2. The teacher should ask the students to write down the ambassador’s name and what they think a scientist does in a typical working day.3. The teacher should explain the structure of the day and the role of the ambassador. The teacher should refer the students to the questions in the Review section and encourage the students to find out what the ambassador does while they are carrying out their activities.4. The ambassador should remind students of the laboratory safety rules.


Station 1: Student Power (7 minutes)

Activity Background InformationHuman-powered generators transform the kinetic energy we produce into electrical energy. Pedaling on the assembly drives a generator inside the device that creates electrical energy. The electrical energy produced is accessible through a standard 120-volt household outlet. For this activity, electrical energy powers a lightbulb. A photometer measures the intensity of the lightbulb. The pedal-powered generator is not a perfectly efficient machine. While all energy is conserved, some of the energy produced is not in a useful form. Rolling friction in the pedals, gears, drive chains, and thermal energy lost in the wires and lightbulb all create an inefficient system.

Materials For each group of four students1 Power box (pedal-powered generator)1 Handheld photometer1 LampElectric wires

Preparation1. Position the pedal-powered generator on the wooden block.2. Connect the generator to the lamp.3. Test the system. Make sure the assembly is powering the lamp. 4. Test the handheld photometer to make sure it measures the light intensity of the bulb.

Procedure1. Have each student take a turn pedaling the power box to light the lamp.2. While one student pedals, the other students record the data using the photometer to measure the light intensity.

Stay SafeEmphasize the individual student’s responsibility for following safe laboratory procedures.

Encourage students to report breakage and accidents as soon as they occur.


Teaching Notes1. It is important for each team member to have a turn on the assembly so that the teams can see that each member has a different power output.2. Remind students that they will be collecting quantitative data in the form of light intensity with the handheld photometer.3. As students fill in the energy flow diagram, remind them that the primary energy source is their peddling.4. Highlight the energy transfer occurring between the lights and the photometer. Ask how this is a model for the Sun and Earth.

Station 2A: Hand Warmer (3.5 minutes)

Activity Background InformationHand warmers are small one-use packets that produce a certain amount of heat. Hand warmers are typically used for outdoor winter activities but can also be used to treat muscle inflammation and other aches and pains. The heat produced from a hand warmer is a result of an exothermic chemical reaction that begins once the plastic package surrounding the hand warmer has been opened. The air interacts with the iron, water, vermiculite, salt, cellulose, and activated carbon to produce a safe amount of heat for 30 minutes to over 10 hours.

Materials For each group of four students4-Hand warmers

Preparation 1. Set out unopened hand warmers. 2. Place an empty container on the table and a trash can under the table for plastic covers.

What Scientists Do

Stay SafeStudents should dispose of the hand warmers properly in the designated container.

The ambassador could talk about how they must think about workflows and processes as a way to improve efficiency and productivity.


Procedure1. Each group gets four hand warmers to open.2. Students open the hand warmers.3. Students move the ingredients around as instructed and observe the temperature change (reaction should take 2–4 minutes).4. Place the heated hand warmer in the empty container and the plastic cover in the trash.

Teaching Notes1. As students open the hand warmer plastic covers, ask them to think about the new chemicals being added.2. Ask students how long they think the hand warmers will produce heat.

Station 2B: Chill Out (3.5 minutes)

Activity Background InformationThe conductive block activity demonstrates that energy can transfer between two systems through direct contact. The first system is the two conductive blocks, and the other system is the ice cubes. The conductive blocks, which are in direct contact with the ice cubes, transfer heat at different rates. The aluminum block should melt the ice at a faster rate than the plywood block. This is because the metal is better at transferring heat.

Students will point the infrared temperature gun at the blocks to collect temperature changes every 30 seconds over the course of three minutes. The infrared temperature gun uses a lens to focus the light produced by the objects on to a detector called a thermopile. The thermopile turns this light into heat and then into electricity. The more electricity produced, the higher the temperature reading on the infrared temperature gun. The data should show each setup approaching the same temperature though a process of thermal equilibrium.

This activity also helps the students understand that some substances move energy better than others do. The aluminum block will feel colder to the touch than the plywood. The evidence from the infrared temperature gun should give the students a chance to confront their misconceptions.

Materials For each group of four students1 Infrared temperature gun1 Aluminum 3-inch-square block painted black 1 Plywood 3-inch-square block painted black


2 Rubber O-rings 2 Ice cubes

For groups to sharePaper towels

Preparation1. Each setup should have two sets of blocks: two aluminum and two plywood. 2. Label the heavier block A and the lighter block B.3. Place the rubber O-rings in the center of the blocks to minimize water spill.4. Have a plastic container filled with ice cubes sitting on the table.5. Make sure the infrared temperature gun is working and measuring in degrees Celsius.

Procedure1. Have students touch both blocks and write down which one they think feels warmer. 2. Have students estimate the temperature of the blocks.3. Have students predict which block will melt the ice cube faster.4. Have students place the ice cubes in the middle of the O-rings sitting on the conductive blocks. 5. Have students use the infrared temperature gun to measure the temperature of the two blocks every 30 seconds for 3 minutes. 6. Observe what happens to the ice on each block.

Teaching Notes1. It is important for students to use touch to compare and contrast the temperatures of the blocks.2. Students should estimate the temperatures of the blocks to compare with their data later.

Stay SafeMake sure the blocks do not have any rough or sharp edges on the surface.


3. Students will use the infrared temperature gun to quantify the temperature changes of the two blocks every 30 seconds for a total of 3 minutes. Make sure students understand how to use the device properly. Students should pull the trigger and point the device in the direction of the block.4. Students should also observe the ice melting on the aluminum block faster than on the plywood block (check time frame for melting).

Station 3: Teacup Stirling Engine (7 minutes)

Activity Background InformationThe teacup Stirling engine activity will introduce the concept of heat transfer through convection. The teacup Stirling engine is able to convert a small temperature difference into motion. The heated air, transferring energy through convection, travels up from the hot water and heats up the bottom of the teacup Stirling engine. As the air heats up inside the bottom of the teacup Stirling engine, it expands and pushes up on the piston. The piston then applies a force and spins the wheel.

What Scientists Do

Stay SafeHave paper towels available at all times in case of water spills.

The ambassador could talk about the importance of matching the thermal properties of materials with the needs of the exper-iment and problem.


The cycle in a teacup Stirling engine is unique because the warm air moves using a displacer. This mechanism causes the air on the top side of the teacup Stirling engine to expand and push down on the piston. The cycle of a teacup Stirling engine will continue to run as long as there is a small temperature difference between the plates. Note that anything that causes a temperature difference would cause motion in the teacup Stirling engine. In the current activity, we use the heated air to heat the bottom plate. Heat from a human hand or even warm sunlight could also cause a similar temperature difference.

Materials For each group of four students4 Safety goggles1 Teacup Stirling engine1 Electric plastic kettle water heater2 Heat-resistant gloves1 Tachometer1 Infrared temperature gun2 CupsReflective tapeWater

Preparation1. For this station, students need access to water and an electrical outlet.2. The electrical outlet will be necessary for the electric plastic kettle.3. Place the cups, teacup Stirling engine, and heat-resistant gloves in a box on the lab table.4. Cut a very small piece of reflective tape and place it on the edge of each Sterling engine wheel where it will not interfere with the spinning.

Procedure

1. Have students warm up water in the water heater.2. Before the water starts bubbling, students should pour some into one cup.3. Have students heat water still left in the water heater until it bubbles. Then pour some into the other cup.

Stay SafeEnsure students wear heat-resistant gloves at all times when handling the electric plastic kettle. Ensure students unplug the kettle after use.


4. Have students use the infrared temperature gun to record the temperature.5. Have students set the Sterling engine on top of a cup of water.6. Have students give the bottom of the engine a little time to warm up. (This should take about a minute.)7. After the engine is warm, students should give the wheel a little push.8. The engine should start moving.9. Have students use the tachometer to measure the speed of the wheel. They should point it at a spot where the reflective tape hits.10. When measuring, the tachometer must remain as still as possible. Have students point it in the exact same spot to get an accurate reading.11. Have students record wheel speed in the first column of their table every 30 seconds for 3 minutes.12. Have students record another group’s data in the second column at the end class.

Teaching Notes1. Remind students that the observed data from the tachometer output is quantitative.2. Students can continue to watch the engines and see how the cooler temperature gives off less heat, which makes the engine move slower.3. You can remove the engines (carefully as the bottoms will be warm). Let students see the steam rising from the water. You could let them put their hand over it to feel the heat.4. The teacup Stirling engine is very delicate and will break if rolled or treated improperly. Students should take care when handling it, especially after the bottom plate has been heated by the water.

Station 4A: Radiometer (3.5 minutes)

Activity Background InformationA radiometer is an instrument that detects or measures the intensity of radiation. The radiometer activity demonstrates that energy can transfer between two systems through radiation. When the students turn on the flashlight and point it at the radiometer, the light rays will hit the black and white fans inside the radiometer. These structures are called vanes. Students will most likely understand that the light from the flashlight causes the vanes to turn. Students may be confused as to why they turn. As the light rays hit the vanes, the black sides of the vanes absorb more of the light than the white sides. The warmer air molecules push off the black side more and around to the other side of the vanes. The difference produces a spinning movement in the radiometer. Different light intensities affect the spinning. The more intense the light, the faster the vanes of the radiometer will spin.


Materials For each group of four students1 Flashlight1 Radiometer

Preparation1. Make sure the radiometer’s vanes spin when light hits them and that the glass is not cracked.

Procedure1. Have students take the radiometer out of the box and examine the vanes (small black and white fans). 2. Have students turn on the flashlight and point the beam of light at the radiometer. 3. Have students record their observations.4. Have students change the distance between the flashlight and the radiometer. They should observe and record what happens.

Teaching Notes1. Students should notice that the speed of the vanes changes when the flashlight and radiometer are farther apart.2. Students should be encouraged to think about the radiometer as a closed system so that they focus on the radiant energy entering the system.

Station 4B: Solar Cell (3.5 minutes)

Activity Background InformationSolar cells (photovoltaic cells) use radiant energy and change it directly into electrical energy. Many different materials allow solar cells to function. In the simplest form, manufactured silicon absorbs the radiant energy. This radiant energy excites the electrons in the silicon.

Stay SafeRadiometers are made of glass and can break if rolled or handled improperly. If the glass does break, students should contact the teacher or ambassador immediately to clean up the broken pieces. Make sure students return the radiometer to its original container after each use.


These excited electrons do one of two things:

1) they produce a small amount of heat as they return to their orbital level, or 2) they travel through the cell until they contact an electrode.

This mass movement of electrons to the electrodes produces an electric current. The electric current that a single solar cell produces can be small. In large quantities, many cells can power all the electrical needs for a city.

Materials For each group of four students1 Hand crank flashlight1 Solar cell1 Multimeter 4 Alligator clips with test leads

Preparation1. Place all of the materials on tables. 2. Make sure the hand crank flashlight and the multimeter are working properly.

Procedure1. Have students set the multimeter to DC voltage and plug the leads into the central and right inputs of the multimeter.2. Have students connect the two wires of a solar cell to the two leads of a multimeter.3. Have students observe the voltage first by covering the solar cell with a hand then by exposing it to room lighting. Have students record the voltage.4. Have students set the multimeter to DC current (10 mA scale) and plug the leads into the central and left inputs of the multimeter.5. Observe the current by exposing the solar cell to the light coming from the hand crank flashlight. Have students record the current.6. Have students repeat step 5 but expose the solar cell to room lighting.

Teaching Notes1. You may have to remind students how to use the multimeter and plug in the leads.2. Also, remind students that they have to reset the multimeter to DC current (10mA scale).3. Students need to collect data from an area of darkness, from regular light from the classroom, and from light coming from the hand crank flashlight.


Review (5 minutes) 1. After clean up, the teacher should tell students they will go over the experiments and review their model in the next lesson.2. Have students briefly share the data they collected and discuss observations with their group. 3. Give students a few minutes to answer the questions in the Review section in the Student Guide. 4. The ambassador should talk about what he or she does, making connections to the practices the students used during the lesson. This could include collecting quantitative and qualitative data, looking for evidence, and constructing explanations.

Stay SafeTell students not to touch any open or frayed wires in a closed circuit.

Ensure students do not put the solar cell too close to the light source because too much heat can damage the cell.


Lesson 3: Model Evaluation

Lesson OverviewIn the final lesson, students will refine the original model they developed. Students should change their models based on their experiences with the activities in Lesson 2. The students will also test the predictions they made. Extending Your Knowledge and Extension Activities sections are both provided at the end of lesson.

Preparation1. Set up the Marble Dash track in the middle of the classroom. Make certain all the marbles will travel the entire length of the track and through the speed sensor.2. Roll the marble down the track a few times to ensure the speed sensor is working properly.

Let’s Get Started (15 minutes)1. Ask students to open up their Student Guide. Provide time for students to answer any unresolved questions and discuss the experiments from Lesson 2 with their small groups. Teachers should circulate among the groups and provide direction and guidance as needed until all students have completed the Review questions. 2. Guide students in a very brief discussion of some of the key concepts from Lesson 2. Ask questions about the energy transformations and energy transfer associated with individual experiments. For example, ask students about what they observed with the teacup Stirling engine. Examples of questions are:

What type of energy do you think it started with? What happened? What type of energy transfer do you think occurred?

These questions will encourage additional comments by the class.

3. After a few minutes of discussion, have students review their models from Lesson 1. Give them a few minutes to reflect individually on their marble track drawing and prediction. Give them time to draw a new model using what they observed in Lesson 2. Their new models should be more refined than in Lesson 1. Have them make a new prediction if necessary. 4. After students have completed their revisions, have them discuss their new models and predictions with a partner or small group. These discussions will allow time for students to compare and contrast different models and explain their changes to earlier models.


5. Ask open-ended questions to the entire class such as:

How did your ideas change when you discussed your model with your group? What were some of the limitations of your original model?

Marble Dash (15 minutes)

Activity Background InformationPlease refer to the Background Information from Lesson 1. Pay particular attention to the section detailing gravitational potential energy.

MaterialsFor the teacher1 Projectile ramp2 Marbles (equal size, one with more mass)1 BeeSpi V photogate timer

Procedure1. Roll a marble with twice the mass as the original from the same height three times and write down the speeds on the board. 2. Roll a marble with the same mass as the original from twice the height three times and write down the speeds on the board. Ask students to return to their seats after the testing.3. Have students record the results of the experiment and review the accuracy of their predictions in question 3 of What Is Going On.4. Prompt students to the answer the Reflection question. 5. Lead the class in reading Extending Your Knowledge, which is about a unique application of energy transformation.

This is a good opportunity to stress the importance of commu-nication in science. Scientists collaborate with other scientists to share ideas and challenge each other’s ideas. They defend their ideas, but they are open to other ideas supported by evi-dence. This advances scientific understanding.

What Scientists Do


Teaching Notes1. Ask open-ended questions to the entire class such as: How would you change your model after today’s demonstration? 2. Before you start reading Extending Your Knowledge, ask students to identify key concepts and applications of this new technology on the margins of their Student Guide. Once the teacher is finished reading, ask students to explore possible applications of this technology.

Reflection (10 minutes)Students should be able to:

Distinguish between kinetic and potential energy. Discuss the different ways energy can be stored. Apply an energy flow diagram to show how energy can transform from one form into

another. Use evidence to describe the three ways energy can transfer between systems.

Extension Activities Have students design an experiment that will determine which type of energy transfer is

most efficient in “moving the heat.” Students could also explore conductors and insulators by designing wetsuits. Include hypothermia as a possible real-world application of their experiment.

Discuss energy transformations and energy transfer for refrigerators, generators, heat pumps, and/or air conditioners.

Explore the design and development of the kinetic watch. Discuss possible applications of this technology especially in terms of wearable technology.

Have students think about how remote wireless charging stations work and how they have changed our lives. Think about how often we are plugged in!

Challenge students to consider what steps and design modifications they would introduce to the pedal-powered generator to make it more efficient.

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