A large rock on the top of a mountain has potential energy. If a small amount of energy sets the rock in motion, this potential energy is converted to kinetic energy. The following picture is a large balanced rock in Leslie Gulch in Oregon.
The water stored behind a dam has potential energy, which can be converted to electrical energy. Electrical energy arises from the flow of electric current. This current may force a wire to heat up and emit energy in the form of heat and visible light. It may pass through a coil and produce a magnetic field, which in turn will cause a motor to run.
Chemical compounds have potential energy in the bonds between atoms. Some chemical reactions release energy in the form of heat. These reactions are called exothermic reactions. A common example of this is the burning of a fuel such as coal or wood. A battery converts chemical energy into electrical energy when a contact is made between the electrodes. The following heartbreaking picture of the horror of forest fires was taken in the Bitterroot National Forest in Montana on August 6, 2000 by a fire behavior analyst from Fairbanks, Alaska by the name of John McColgan.
most common type of work experienced in chemical reactions is an increase in the
volume of the system. A chemical reaction also does work by moving electrons or