Question

If you tie a bowling ball onto the ceiling and let it swing why doesn't it hit you in the face?

Answer 1

The bowling ball starts with a certain amount of potential energy. It gets this energy because someone had to lift it up to hang it. Bowling balls are heavy and you have to do work to get it up in the air. Whenever we do work on something, we are giving it energy. When you let go of the ball, it swings downward like a pendulum. As it starts swinging, the energy changes from potential energy to kinetic, or moving, energy. The total amount of energy, moving plus stored, stays the same; it only changes form. When the ball swings back to where it started, the energy changes back to potential energy. Since the total energy has to stay constant, the kinetic energy of the ball must be zero and the ball must stop moving. It can’t hit you