Kinetic and Potential Energy

Test Form A

  1. Kinetic energy is energy of _________.

    2.  

  2. Potential energy is _________ energy.

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  3. The change in potential energy is ___________ the opposite of change in kinetic energy.

    4.  

  4. Josh has a 20-kilogram weight that he dropped off the roof of his house. It hit one side of a lever and the other side launched a ten-kilogram object at 40 meters per second. How high was it when he dropped it?

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  5. Adam hits a baseball at 30 meters per second. His bat has a mass of 12 kilograms. He swung the bat at 10 meters per second, what is the mass of the ball?

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  6. Roger dropped a ball out of the top of a tree. The ball was 27 meters up and had a mass of .5 kilograms. How much potential energy did it have?

 

 

 

 

Kinetic and Potential Energy

Test Form B

  1. Josh has a 30-kilogram weight that he dropped off the roof of his house. It hit one side of a lever and the other side launched a ten-kilogram object at 20 meters per second. How high was it before he dropped it?

    2.  

     

     

     

  2. Adam hits a baseball at 50 meters per second. His bat has a mass of 10 kilograms. He swung the bat at 15 meters per second, what is the mass of the ball?

    3.  

     

     

     

     

  3. Roger dropped a ball out of the top of a tree. The ball was 17 meters up and had a mass of .25 kilograms. How much potential energy did it have?

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  4. Gravitational acceleration is a ___________.

    5.  

  5. __________ must be shown in all kinetic and potential energy problems.

    6.  

  6. __________ has more effect on kinetic energy than _____________.

 

Kinetic and Potential Energy

Test Form A

Answer Key

  1. motion
  3. Solution: 40.81 meters

    4. KE = .5mv2

    KE of launched object = .5(10 kg)(40 m/s)2

    KE = (5 kg)(1600 m2/s2)

    KE = 8000 kg m2/s2

    KE on the other side is 8000 kg m2/s2

    PE at start equals KE at end

    8000 kg m2/s2 = (20 kg)(9.8 m/s2)h

    Solve for h

    400 m2/s2 = (9.8 m/s2)h

    h = 40.81 meters

  4. Solution: 132.3 joules

    5. PE of the ball = (.5 kg)(9.8 m/s2)(27 m)

    PE = (4.9 kg m/s2)(27 m)

    PE = 132.3 kg m2/s2 or 132.3 joules

  5. Solution: 1.333 kilograms

KE = .5mv2

KE of bat = .5(12 kg)(10 m/s)2

KE = (6 kg)(100 m2/s2)

KE = 600 kg m2/s2

KE of ball is 600 kg m2/s2

600 kg m2/s2 = .5m(30 m/s)2

Solve for m

1200 kg m2/s2 = m(900 m2/s2)

m = 1.333 kilograms

 

Kinetic and Potential Energy

Test Form B

Answer Key

  1. Solution: 6.803 meters

    2. KE of launched object = .5(10 kg)(20 m/s)2

    KE = (5 kg)(400 m2/s2)

    KE = 2000 kg m2/s2

    KE on the other side is 2000 kg m2/s2

    PE at start equals KE at end

    2000 kg m2/s2 = (30 kg)(9.8 m/s2)h

    Solve for h

    66.666 m2/s2 = (9.8 m/s2)h

    h = 6.803 meters

  2. Solution: .6 kilograms

    3. KE of bat = .5(15 kg)(10 m/s)2

    KE = (7.5 kg)(100 m2/s2)

    KE = 750 kg m2/s2

    KE of ball is 750 kg m2/s2

    750 kg m2/s2 = .5m(50 m/s)2

    Solve for m

    1500 kg m2/s2 = m(2500 m2/s2)

    m = .6 kilograms

  3. Solution: 66.15 joules

    4. PE of the ball = (.25 kg)(9.8 m/s2)(17 m)

    PE = (2.45 kg m/s2)(27 m)

    PE = 66.15 kg m2/s2 or 66.15 joules

    ZE=+2>units
  4. velocity; mass