Momentum Review

A cannonball with a mass of 1.0 kilogram is fired horizontally from a 500.-kilogram cannon, initially at rest, on a horizontal, frictionless surface. The cannonball is acted on by an average force of 8.0 × 10³ newtons for 1.0 × 10⁻¹ second. What is the magnitude of the change in momentum of the cannonball during firing?

• 0 kg•m/s

• 8.0 × 10² kg•m/s

• 8.0 × 10³ kg•m/s

• 8.0 × 10⁴ kg•m/s

A blue lab cart is traveling west on a track when it collides with and sticks to a red lab cart traveling east. The magnitude of the momentum of the blue cart before the collision is 2.0 kilogram • meters per second, and the magnitude of the momentum of the red cart before the collision is 3.0 kilogram • meters per second. The magnitude of the total momentum of the two carts after the collision is

• 1.0 kg • m/s

• 2.0 kg • m/s

• 3.0 kg • m/s

• 5.0 kg • m/s

A 1.5-kilogram cart initially moves at 2.0 meters per second. It is brought to rest by a constant net force in 0.30 second. What is the magnitude of the net force?

• 0.40 N

• 0.90 N

• 10. N

• 15 N

A 5.00-kilogram block slides along a horizontal, frictionless surface at 10.0 meters per second for 4.00 seconds. The magnitude of the block’s momentum is

• 200. kg·m/s

• 50.0 kg·m/s

• 20.0 kg·m/s

• 12.5 kg·m/s

A 75-kilogram hockey player is skating across the ice at a speed of 6.0 meters per second. What is the magnitude of the average force required to stop the player in 0.65 second?

• 120 N

• 290 N

• 690 N

• 920 N

A 3.1-kilogram gun initially at rest is free to move. When a 0.015-kilogram bullet leaves the gun with a speed of 500 meters per second, what is the speed of the gun?

• 0.0 m/s

• 2.4 m/s

• 7.5 m/s

• 500. m/s

Calculate the magnitude of the impulse applied to a 0.75-kilogram cart to change its velocity from 0.50 meter per second east to 2.00 meters per second east.

• J = 1.5 N•s

• J = 1.2 N•s

• J = 0.5 N•s

• J = 0.35 N•s

A woman with horizontal velocity v₁ jumps off a dock into a stationary boat. After landing in the boat, the woman and the boat move with velocity v₂. Compared to velocity v₁, velocity v₂ has

• the same magnitude and the same direction

• the same magnitude and opposite direction

• smaller magnitude and the same direction

• larger magnitude and the same direction

A 3.0-kilogram steel block is at rest on a frictionless horizontal surface. A 1.0-kilogram lump of clay is propelled horizontally at 6.0 meters per second toward the block as shown in the diagram. Upon collision, the clay and steel block stick together and move to the right with a speed of

• 1.5 m/s

• 2.0 m/s

• 3.0 m/s

• 6.0 m/s

A 1000.-kilogram empty cart moving with a speed of 6.0 meters per second is about to collide with a stationary loaded cart having a total mass of 5000. kilograms, as shown. After the collision, the carts lock and move together. [Assume friction is negligible.] How does the kinetic energy of the combined carts after the collision compare to the kinetic energy of the carts before the collision?

• The KE of the combined carts after the collision is greater than the KE of the carts before the collision.

• The KE of the combined carts after the collision is less than the KE of the carts before the collision.

• The KE of the combined carts after the collision is the same as the KE of the carts before the collision.