ABSTRACT
As we have learned in the previous chapter, the amount of work done on an object equals the energy transformed from one form to another. The chemical energy in our bodies is transformed into potential energy as we lift a baseball, and this energy is further transformed into kinetic energy as we drop the ball and it falls with increasing speed toward the ground. Energy, then, can be transformed from one form to another. Before the boulder in Figure 5.1 starts rolling down the cliff, its energy is potential. As the boulder falls, its potential energy is continuously converted into kinetic energy. When it reaches the ground below, the boulder has no potential energy.
