Conservation of Momentum Practice Problems Name:
1. In a comic book, Superman carries a bus (with a bomb on board) up into the air, hovers for a second
and then throws the bus over the horizon while he stays hovering. How does this situation break the law
of conservation of momentum? What should have happened instead? Why?
2. Two astronauts in space with a baseball decide to play catch to pass the time. In the language of
conservation of momentum, describe what happens to each astronaut as they start to toss the ball back
3. A 20 kg tennis ball launcher shoots a 0.057 kg tennis ball across a frictionless court. If the tennis
ball’s velocity after it is launched is 36 m/s to the north, what is the velocity of the tennis ball launcher?
4. A 0.008 kg bullet going 400 m/s to the east hits a tin can filled with sand (total mass 5 kg) and gets
stuck inside in an inelastic collision. Assuming there is no friction, how fast is the can (and the bullet)
moving after the collision?
5. A 110 kg running back carries the ball south at 8 m/s. A 130 kg linebacker runs to make the tackle
going north at 5 m/s. In their collision, the linebacker wraps his arms around the runner and makes it an
inelastic collision. How fast are they moving right after the collision (before they fall to the ground)?
6. A 2000 kg SUV traveling at 7 m/s south runs into the rear end of an 800 kg compact car sitting at a
stop light in an elastic collision. If the compact car is going forward at 7 m/s right after the collision,
how fast is the SUV traveling?
7. Teresa and Samir are driving bumper cars. They spot each other across the rink and head straight for
each other at full speed. Samir and his car (130 kg total) head east at 3.5 m/s while Teresa and her car
(110 kg total) head west at 3.0 m/s. They have an elastic collision when they meet and Samir (and car)
bounces backwards at 2.4 m/s. What is Teresa’s speed after the collision?
8. The cue ball going 9 m/s heads directly toward a 0.17 kg object ball at rest near the pocket. During
the elastic collision, the cue ball stops and the object ball is launched forward at 9 m/s. What is the cue