1, It's much easier to stop a bicycle traveling toward you at 5 km/h than an automobile traveling toward you at the same velocity. Why?

2,Bowling balls come in various masses. Suppose that you try bowling two different balls, one with twice the mass of the other. If you push on them with equal forces, which one will accelerate faster and how much faster?

3, Out in deep space, far from any celestial object that exerts significant gravity, would an astronaut weigh anything? Would that astronaut have a mass?

4, You are pushing a child on a playground swing. If you exert a 50 N force on him as he is swinging away from you, how much force will he exert back on you? Why?

5, As you ride upward in an elevator at a constant velocity, what two forces act on your body, and what is the net force on you?