Study Guide for the Energy Test
Energy is the ability to do work.
Kinetic and Potential Energy
Potential Energy- stored energy, an object at rest and not in motion
(a rock on the edge of a cliff, a ball sitting on a shelf, water behind a dam)
 You can change the potential energy by changing its height or its shape.
 The greater the height above the ground, the more potential energy the object will have.
 The more potential energy something has, the more kinetic energy it will have.
Kinetic Energy- energy of motion (a ball moving through the air, a person running)
 The amount of kinetic energy depends on an object's mass and speed.
 The larger the mass of the object or the greater the object’s speed, the more kinetic
energy the object will have.
Examples of Potential and Kinetic Energy
When ball A is dropped gravitational potential changes into kinetic energy.
At point 1 the train has the greatest potential energy.
At point 5 the ball has the greatest amount of kinetic energy.
At point 3 the ball has the greatest amount of potential energy.
Forms of Energy
1. Electrical energy – energy stored in an outlet. Anything that plugs in uses electrical energy.
Batteries provide electrical energy.
2. Chemical energy - energy that is stored and found in anything that can burn
- fossil fuels, wood, batteries, food or fireworks.
3. Radiant energy – light energy is a form of radiant energy that travels in waves
- solar energy is also form of radiant energy
4. Mechanical energy - the energy of motion used to perform work; movement of objects or
substances from one place to another- running, a fan moving, shutting a door
5. Thermal energy (heat energy) - Thermal energy is related to temperature, the energy of
moving or vibrating molecules.
6. Nuclear energy - the energy stored in the center of atoms
Energy Transformations- occurs when energy changes from one form to another
 When energy changes form, some of the energy is always changed into thermal (heat)
energy.
 The Law of Conservation of Energy - Energy is neither created nor destroyed, only
transformed from one type to another.