Energy may be either potential or kinetic. Potential energy (PE) is energy stored and ready for use. A car stopped at the top of a hill and a water balloon dangling out of an upstairs window have potential energy. Potential energy is measured by the amount of work the object can perform. The other form of energy is kinetic energy (KE). Kinetic energy is the energy of motion. A car rolling downhill and a water balloon falling towards its target have kinetic energy. Because of its greater mass, a falling car has more kinetic energy than a falling water balloon. Similarly, because of its greater velocity, as water balloon that is thrown down will have more kinetic energy than one that is simply dropped from the same height. As these examples show, potential energy can become kinetic energy. Kinetic energy can also be transferred from one object to another: imagine a car or the water balloon striking a ping pong ball and sending it flying. Recall also that kinetic energy comes in six forms - chemical, electrical, radiant, mechanical, nuclear, and thermal- and that each of these forms can be converted into any of the other forms. For example, a battery converts chemical energy into electricity, and a light bulb converts electricity into light and heat.…