1. Two bowling balls hit each other. The mass of the first bowling ball is 3 times larger than the mass of the second bowling ball. If the first bowling ball exerts a force with a magnitude of 200 N on the second bowling ball, how large is the magnitude of the force that the second bowling ball exerts back on the first one? (in N)

2. When you push a box along the floor with a force of 6 N, the box moves at constant speed due to the friction force between the floor and box. When you push the same box (which is subject to the same friction force) with a force of 10 N, the box accelerates at 1 m/s². What is the mass of the box? (in kg)

3. A ball that is dropped from rest is falling down. When the ball hits the ground it has a speed of 10 m/s. What is the speed of the ball (in m/s) half-way to the ground? Neglect air friction.

4. A 250-kg car is parked on a sloped street that makes an angle of 11 degrees with the horizontal direction. How large is the friction force that acts on the car? (in N)

5. Two wooden crates, one of mass m₁ and the other one of five times larger mass m₂ =5 m₁, are connected by a rope that passes over a pulley as shown in the figure.

m1 m2