http://www.ck12.org Chapter 2. Energy ConservationVersion 2
2.4 Key Applications
- In “roller coaster” problems, a cart’s gravitational potential energy at the top of one hill is transformed into
kinetic energy at the next valley. It turns back into potential energy as cart climbs the next hill, and so on. In
reality a fraction of the energy is lost to the tracks and air as heat, which is why the second rise is rarely as big
as the first in amusement parks. - In “pole-vaulter” problems, the athlete’s body breaks down the food molecules to change some of the bonding
energy into energy that is used to power the body. This energy is transformed into kinetic energy as the athlete
gains speed. The kinetic energy can be changed into potential energy as the athlete gains height. - In “pendulum” problems, the gravitational potential energy of the pendulum at its highest point changes to
kinetic energy as it swings to the bottom and then back into potential energy as it swings up. At any in-between
point there is a combination of kinetic energy and potential energy, but the total energy remains constant.