Flashlight Experiment

Chemical and electric potential energy can be demonstrated through a battery in a flashlight. In batteries chemicals are used to separate electrons (- charge) from protons (+ charge), momentarily moving them. The separated positive and negative electric charges of a battery represent another form of potential energy called electric potential energy. When a battery is connected to an electrical circuit (such as a flashlight being turned on), the electrons leave the negative terminal of the battery and move (flow) through the circuit to the positive terminal.

In energy terms, electrical potential energy in the battery is converted into kinetic energy of moving electrons. Think back to the waterfall analogy used to discuss voltage and current. The voltage is the height of the water fall and the current is the falling water (flowing electrons). The electrons' kinetic energy is then converted into another form, such as light with the flashlight. (taken from "Potentially Kinetic More About Batteries," KEEP Activity Guide.)