1. question t3-1
(Points: 1) Kinetic energy is defined to be one-half the

1. speed
2. velocity
3. mass times the speed squared
4. mass times the acceleration
5. none of above Save Answer
2. question t3-2
(Points: 1) When a star undergoes a supernova explosion, the total energy of the universe

1. increase
2. decrease
3. no change
4. increase all the time
5. none of above Save Answer
3. question t3-3
(Points: 1) Which has the greater kinetic energy, a heavy truck at rest or a moving roller skate?

1. the heavy truck
2. the roller skate
3. The kinetic energies are equal.
4. heavy truck always has greater kinetic energy.
5. none of above Save Answer
4. question t3-4
(Points: 1) If a sports car with a mass of 1000 kg travels down the road with a speed of 20 m/s, its kinetic energy is 200,000

1. kg/(m/s)2
2. kg•s2/m2
3. kg•m/s
4. kg•m2/s2
5. none of above Save Answer
5. question t3-5
(Points: 1) A sports car with a mass of 1000 kg travels down the road with a speed of 20 m/s. Which is larger, its momentum or its kinetic energy?

1. momentum
2. kinetic energy
3. They are equal.
4. The two cannot be compared
5. none of above Save Answer
6. question t3-6
(Points: 1) What is the kinetic energy of an 80-kg sprinter running at 10 m/s?

1. 40000 J
2. 4000 J
3. 8000 J
4. 10000 J
5. 60000 J Save Answer
7. question t3-7
(Points: 1) Assume that a red car has a mass of 4000 kg and a white car has a mass of 2000 kg. If both cars are traveling at the same velocity,

1. their kinetic energies are equal.
2. their momenta are equal.
3. the red car's kinetic energy is twice as big.
4. the white car's kinetic energy is twice as big
5. none of above Save Answer
8. question t3-8
(Points: 1) Assume that two cars have the same mass, but that the blue car has half the speed of the red car. We then know that the red car has ____ kinetic energy as the