Conservation Laws

Energy that is stored due to the position of an object may be called ____ energy.
1. kinetic
2. potential
3. radiant
4. nuclear
A 20-kilogram object falls 2.0 meters to the floor. At what point in its fall does the kinetic energy of a body equal its potential energy?
1. At all points of the fall
2. Very nearly at the top of the fall
3. Halfway to the floor
4. Just the instant before it hits the floor
An object falls without friction near Earth’s surface. The loss of its potential energy is equal to its ____.
1. loss of height
2. loss of mass
3. gain in kinetic energy
4. gain in velocity
The ability to cause change is defined as ____.
1. force; measured in newtons
2. power; measured in watts
3. energy; measured in joules
4. impulse; measured in newton-seconds
Potential energy increases as a marble ____.
1. slows rolling up an incline
2. increases speed down an incline
3. rolls at uniform speed on a level table
4. sits motionless on the floor
What does the value “70-kilogram” represent?
1. mass
2. change in height
3. force
4. change in speed
What does the value “2.0 meters” represent?
1. mass
2. change in height
3. force
4. change in speed
What is g?
1. the acceleration due to gravity
2. about 10 m/s^2 down
3. about -10 m/s^2
4. all of these
Which equation would allow you to calculate the potential energy of the barbell?
1. red
2. green
3. blue
4. purple
The increase in the barbell’s potential energy is about ____.
1. 35 joules
2. 140 joules
3. 350 joules
4. 1,400 joules
What does the value “0.25-kilogram” represent?
1. mass
2. distance
3. force
4. speed
What does the value “2.5 meters per second” represent?
1. mass
2. distance
3. force
4. speed
Which equation would allow you to calculate the mechanical kinetic energy of the rolling ball?
1. red
2. green
3. blue
4. violet
The amount of mechanical kinetic energy possessed by the rolling ball is ____ joules.
1. 0.31
2. 0.63
3. 0.78
4. 1.6
If the speed of a moving object doubles, the amount of mechanical kinetic energy that it possesses ____.
1. increases by two times
2. increases by four times
3. decreases by two times
4. decreases by four times
If the speed of a moving object triples, the amount of mechanical kinetic energy that it possesses ____.
1. increases by three times
2. increases by nine times
3. decreases by three times
4. decreases by nine times
When the brakes are fully applied, compared to the energy required to stop a car going 30 miles per hour, the energy needed to stop a car going 90 miles per hour is ____.
1. 3 times as great
2. 6 times as great
3. 9 times as great
4. the same
An object that has kinetic energy must be ____.
1. falling
2. at an elevated position
3. at rest
4. moving
Two objects, A and B, have the same size and shape, but A is twice as heavy as B. When they are dropped simultaneously from a tower, they reach the ground at the same time, but A has greater ____.
1. acceleration
2. kinetic energy
3. speed
4. all of these

Conservation Laws - Energy

Review Questions