Learning about these two forms of energy is extremely important in understanding why man can obtain the usable energy from things like waterfalls and spinning turbines. Power plants serve to convert these physical forms of energy into energy to run our TVs and cook food in the microwave -- electricity!

Kinetic Energy (KE) is the name for energy associated with moving objects. A good way to remember this is by the formula KE=(1/2)mv2, where m; is the mass of the object and v; is the velocity of the object. If you remember the formula, you will remember that kinetic energy is dependent upon velocity and mass, and thus has to do with moving objects.

Potential Energy (PE) is the name for energy stored in an object--or, the "potential" of an object to do work. For instance, a rock at the top of a cliff has more potential energy than one on the ground, because you could drop the rock off of the cliff and hit something below (converting the potential energy to kinetic).

The picture below of the world-famous Horseshoe Fall at Niagara Falls will further illustrate the difference between kinetic and potential energy. In this case, the two forms of energy are experienced by molecules of water. Point your mouse onto the photo (do not click) and watch the bottom status line of your browser.

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What you're missing here is basically that there is a lot of potential energy at the top of the waterfall, while there's little kinetic energy. As you move down, the potential energy gradually decreases, while the kinetic energy increases proportionately. At the very bottom of the waterfall, there is high kinetic energy, but very little potential energy.

courtesy Shirley Holtsmark's Niagara Falls Photo Gallery