1. Two skaters, Elena and Tara, face each other on the ice. Elena has a mass of 57.4 kg, and Tara has a mass of 48.3 kg. Both are motionless until they push away with a force of 33 N. Then Elena has a velocity of 1.4 m/s. What is Tara's velocity?
2. The angular momentum of a spinning wheel decreases from 8.4 kg-m'/s to 4.7 kg.m'/s over a period of 2.1 s. What is the angular impulse that slowed the wheel?
3. A 0.068-kg ball strikes a wall with a velocity of 22.1 m/s. The wall stops the ball in 0.36 s. What is the magnitude of the force applied by the wall on the ball?
4. A 945-kg car is moving along a straight highway with a velocity of 98 km/h. The driver applies the brakes and reduces the car's speed to 36 km/h in 8.5 s. What is the impulse on the car?
5. The diagram shows two 0.17-kg billiard balls. The white ball strikes the stationary black ball and moves off at an angle 60.0 north of east. The black ball moves off at an angle 48.2 south of east. (diagram is attached)

• What is the white ball's initial velocity?

6. A 2100-kg car is traveling at 25 m/s when it crashes into the rear end of a 1650-kg car traveling at 21 m/s in the same direction on ice. The two cars become stuck together and slide on the ice. How fast do the two cars move together immediately after the collision?

7. Two hockey players, Z and Q, are standing face-to-face and stationary on the ice. Skater Z has a mass of 72.5 kg. Skater Q has a mass of 65.3 kg. Skater Z shoves Skater Q. Which statement below best represents the skaters' momenta and motion after the shove?

A. The momenta of the skaters after the shove are equal in magnitude but opposite in direction. Skater Z's motion is an example of recoil.

B. The momenta of the skaters after the shove are equal in magnitude and in direction.

C. The momenta of the skaters after the shove are equal in magnitude but opposite in direction. Skater O's motion is an example of recoil.

D. The momenta of the skaters after the shove are of inverse proportion in magnitude and opposite in direction. The motion of both skaters are examples of recoil.

• Use the diagram attached of the cars 8 and 9.

8. The diagram shows a car traveling north colliding with a car traveling east. After the collision, the cars stick together and move off in another direction. What is the magnitude of the cars' final momentum?

9. At what angle north of east is the cars' direction of motion after the collision?