Warm-Up:

Warm-Up:

1. Give an example of something with speed.2. Give an example of something with velocity.

Warm-Up:

1. What would be the velocity of a bird that flies 10 miles South in 2 hours?2. What is the acceleration of a car that goes from a stop to 100km/h in 6 seconds?

Warm-Up:

1. What is the difference between speed and velocity?2. What is acceleration?

Speed is a rate

Speed = distance time

Average Speed = total distancetotal time

Velocity = speed in a particular direction

Velocity changes if speed or direction change

Acceleration: the rate at which velocity changes

Acceleration=

final velocity – starting velocitytime it takes to change velocity

______ – distance over time

_______ – speed and direction

__________ – the rate at which velocity changes

Calculate the total velocity for each of the passengers.

Airplane: 800km/h westAirplane: 800km/h west

4km/h west4km/h west5km/h east5km/h east

0km/h west0km/h west

QUICK REVIEWWhat information must you know in order to

calculate speed?

What is the error in the following statement:The velocity of the car is 55km/hr.

DS T

Cover the one you’re looking for.

Application: Speed Calculations1.A pitcher threw a baseball 150m in 2 seconds. How fast was the ball going?2.A girl can run 50m/s. How long will it take her to run 1000m?3.You drove 80km/h for 3 hours. How far did you go?

Application: Speed Calculations1.A car drove 120 miles in 3 hours. How fast was it going?2.A sprinter can run 60 m/s. How long will it take her to run 600m?3.You drove 50 mi/h for 8 hours. How far did you go?

Everybody Writes!In your own words, describe the motion shown by each graph. (Hint: Be sure to look at the labels on the x and y axis.) Graph 1

Everybody Writes!In your own words, describe the motion shown by each graph. (Hint: Be sure to look at the labels on the x and y axis.) Graph 2

Everybody Writes!In your own words, describe the motion shown by each graph. (Hint: Be sure to look at the labels on the x and y axis.) Graph 3

Everybody Writes!In your own words, describe the motion shown by each graph. (Hint: Be sure to look at the labels on the x and y axis.) Graph 4

Application: Speed CalculationsHow fast would you have to drive to go from Atlanta to New York (900 miles) in 10 hours?

A red car drove 150km at a speed of 50km/h. A blue car drove 300km at a speed of 75km/h. Which car reached its destination first?

Application: Speed CalculationsA plane flies 100 km east for 10 minutes, then 200 km for 10 minutes, and then 50 km for 5 minutes. What is the plane's average velocity?Did the plane accelerate?

Application: Speed CalculationsYou will drive to a town that is 100km away. Half the trip you will be able to drive 100km/h (on the highway) and half the trip you will drive 50km/h (going through small towns). How long will it take you to get there? Show your work!

Distance-Time Graphs

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Graph showing the speed of a car

---- Car 1

---- Car 21. Which car drove at a

constant speed?

2. Which car accelerated?

3. Which car is faster? How do you know?

4. Which car drove farther after 1 hour? After 6 hours?

Distance-Time Graphs

Calculate the average speed Calculate the average speed at each point:at each point:A.A.__________________B.B.__________________C.C.__________________D.D.__________________

Did the car accelerate or stay Did the car accelerate or stay at a constant speed? How at a constant speed? How do you know?do you know?

AA

DD

CC

BB

Distance-Time GraphsThe following graph shows the distance Kyle traveled on his bicycle trip and the amount of time it took him to travel that distance.

1. During which 5-minute interval did Kyle achieve the greatest average speed?

2. What may have happened between t = 10 and t = 15 minutes?

1. What two things must you know to calculate speed?2. What is wrong with the following statement:

The velocity of a car is 100km/h3. Turning left, slowing down, and speeding up are all examples of

__________. 4. How fast would you have to drive to go from Atlanta to New

York (900 miles) in 9 hours?5. A red car drove 400km at a speed of 50km/h. A blue car drove

600km at a speed of 75km/h. Which car reached its destination first? YOU MUST SHOW YOUR WORK FOR CREDIT!

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Graph showing the speed of cars

---- Blue Car

---- Red Car

6. Which car drove the farthest after 1 hour?7. How far did each car drive in 7 hours?

• Red Car _____• Blue Car: ____

8. Which car accelerated?

9. Which car stayed at a constant speed?

10. What best explains the motion of the red car between t=1 and t=4?

Practice:

A golf ball is hit north off a tee and 2 seconds later, it is traveling 300 m/s

Practice:

A car is traveling south at 20 mph and after 10 seconds is traveling 60 mph

Target: (#21)Read about the Great Pyramids on pg. 186.1. What are the pyramids made from?

2. How did the Egyptians lift the blocks?

Warm-up:

What is work?

Notes: Work & Machines

Work occurs when a force causes an object to move in the direction of the force

Force & Motion must be in the same direction for work to occur

Work = Force x Distance

Work is measured in joules (j)

Work = Force x Distance

1. How much work is done when you apply a force of 10 N to lift a bag 1 meter?

2. How much work is done when a force of 200 N is used to move a car 20 meters?

Power is the rate at which work is done

The unit for power is the watt.

Power = WorkTime

Power = WorkTime

3. If you do 60 J of work in 10 seconds, what is your power?

Warm-Up:1. How much work (in joules) does a person do if they apply a 100N force a distance of 10 meters?

2. How much power does a horse generate if it does 600 joules of work in 60 seconds?

A machine is a device that makes work easier by changing the size or direction of the force

The work you do on a machine is called the work input (input force).

The work done by the machine is called work out put (output force).

Machines don’t reduce the work, they change the size or direction of the force

The force-distance trade-off: force or distance can increase, but not together

Target

1. If you exert 10 N of force on an object and the object does not move, did you do any work?

2. What units are used for power?

Target (#24)

1. The work done on a machine is called the __________ __________.

2. The work done by the machine is called the ___________ _________.

The mechanical advantage tells you how many times the machine multiplies the force

MA = Output Force Input Force

Mechanical Efficiency compares work output with work input.

ME = Work Output X 100 Work Input

A lever is a bar that pivots around a fixed point called a fulcrum

First class: fulcrum is between the input force and the load

Second class: The load is between the fulcrum and the input force

Third class: The input is between the fulcrum and the load

Warm-Up:1. If a car drives in a straight line and its speed increases from 6m/s to 12m/s in 3 seconds, what is his acceleration?

2. If a ball rolls 10 meters in 2 seconds, what is its velocity?

An inclined plane has a straight, slanted surface

A wedge is a double inclined plane that moves

A screw is an inclined plane wrapped in a spiral

A wheel and axle consists of two circular objects of different sizes

A pulley consists of a grooved wheel that holds a rope or cable

A compound machine is made of two or more simple machines

Target1. What do machines do?

2. What is a compound machine?

Warm-Up

Warm Up

If it takes 100N to move a box, how long will it take a 20W motor to move the box 5m?

What is the efficiency of a block and tackle if you pull 20m of rope with a force of 600N to raise a 200kg piano 5m?

Target (#26)1. What is a simple machine that is flat with a sloped surface?

2. Which simple machine uses a rope and a grooved wheel?

Target (#28)Tell which simple machine you would use for each:1. Hanging a flagpole2. Loading a car onto a trailer3. Drilling a hole in a board4. Raising the sail of a boat5. Moving a large rock

Warm-Up:

1. If you are riding a skateboard, are you doing work? Explain.

2. If you ride a bicycle to school rather than walk to school, are you doing less work? Explain.

Copy these questions onto a separate piece of paper:1. What is a “Rube Goldberg Machine”?2. What chemical reaction did they use?3. List two simple machines in the machine.

Target: (#33)

1. How much work is done if while climbing the stairs you exert 500N of force for a distance of 2M?

2. How much power do you generate if it took you 10 seconds to do that?

Target: 1. If you did 1000 J of work on a box using 500 N of force, what distance would the box travel?

2. What is the power generated by 400 Joules of work for 40 seconds?

1. To determine the acceleration of an object, you must calculate the change in velocity during each unit of ___________.

2. What two things affect gravity?

3. Which kind of forces are exerted on an object if there is a net force of zero

4. Which two forces operate to keep a moon in orbit around a planet?

A. inertia and gravity B. inertia and friction C. friction and gravity D. distance and gravity

5. A complex machine is a system made up of two or more simple machines. Which of these machines includes both a lever and a wedge?

A. wheelbarrow B. scissors C. doorknob D. pencil sharpener

6. A wheel and axle is a simple machine made up of two circular objects of different sizes. How does a wheel and axle make work easier?

A. It changes the direction of the force B. It multiplies the effort force. C. It multiplies the distance over which the

force must be exerted. D. It changes both the direction and the size of

the effort force.

1. A man applies a force of 500N to push a truck 100M down the street. How much work does he do?2. In which situation would you do more work:

-Lifting a 75N bowling ball 2M off the floor-Lifting two 50N bowling balls 1M off the

floor3. You push a 75N box 3M across the floor. How much work have you done?4. What is the power of a small motor that can do 4500J of work in 25 seconds?5. Work depends on _________and________.

6. Explain the difference between work & power.7. You apply 200N to a machine, and the machine applies 2000N to an object. What is its mechanical advantage? 8. You apply 10 N to a machine, and the machine applies 10N to another object. What is the mechanical advantage? Can this machine be useful? Why?9. How does a machine make work easier?10. List and gives of examples of the six simple machines.11. What is a compound machine?

Target: Copy these film questions:1. What unit is used to measure the diameter of an atom?2. Where did the meter come from?3. Why do we use the metric system?4. What things do we measure the most?