Momentum and Collisions Review

1. Momentum and Collisions Review

2. A roller coaster climbs up a hill at 4 m/s and then zips down the hill at 30 m/s. The momentum of the roller coaster • is greater up the hill than down the hill. • is greater down the hill than up the hill. • remains the same throughout the ride. • is zero throughout the ride.

3. A force is applied to stop a moving shopping cart. Increasing the time interval over which the force is applied • requires a greater force. • has no effect on the force needed. • requires a smaller force. • requires the same force.

4. When the total initial momentum before a collision is zero, which of the following cannot be true? • The objects are both moving in opposite directions. • The total momentum after the collision will be zero. • Both objects are moving in the same direction before the collision. • All of the above statements are true

5. A moderate force will break an egg. However, an egg dropped on the road usually breaks, while one dropped on the grass usually does not break because for the egg dropped on the grass, • the change in momentum is greater. • the change in momentum is less. • the time interval for stopping is greater. • the time interval for stopping is less.

6. A large moving ball collides with a small stationary ball. The momentum • of the large ball decreases, and the momentum of the small ball increases. • of both balls increase. • of the large ball increases, and the momentum of the small ball decreases. • does not change for either ball.

7. In a two-body collision in a closed system, • momentum is always conserved. • kinetic energy is always conserved. • neither momentum nor kinetic energy is conserved. • both momentum and kinetic energy are conserved.

8. The impulse experienced by a body is equivalent to its change in: • velocity. • kinetic energy. • momentum. • None of the above choices are valid.

9. A valid unit for momentum is which of the following? • kg×m/s2 • kg/m2 • kg×m/s • N×m

10. The units of impulse are equivalent to: • those of energy. • N×m. • kg×m/s. • those of force.

11. If the momentum of an object is tripled, its kinetic energy will change by what factor? • zero • one-third • three • nine

12. After analyzing a collision, you find that the kinetic energy was conserved. You can assume the collision was: • Perfectly elastic • Perfectly inelastic • Somewhat inelastic • Unable to be determined

13. After analyzing a collision, you find that the momentum was conserved. You can assume the collision was: • Perfectly elastic • Perfectly inelastic • Somewhat inelastic • Unable to be determined