| A | B |
|---|
| energy | the ability to cause change;when something is able to change its environment or itself, it has energy. |
| gravity | the attractive force between any two objects that have mass; on Earth, the acceleration due to gravity is 9.8m/s2 |
| kinetic energy | the energy a moving object has because of its motion |
| joule | the SI unit of energy, abbreviated J |
| potential energy | stored energy due to position or condition |
| elastic potential energy | energy stored by something that can stretch or compress, such as a rubber band or spring |
| chemical potential energy | energy stored in the bonds that hold atoms together |
| gravitational potential energy | energy stored by objects due to their position above the ground; abbreviated GPE |
| Calorie | the energy required to raise the temperature of one kilogram of water 1 degree C, equivalent to about 4,184 joules |
| friction | a force that opposes the sliding motion between two surfaces that are touching. |
| mechanical energy | the total amount of potential and kinetic energy in a system |
| law of conservation of energy | energy can change from one form to another but the total amount of energy never changes; energy is never destroyed |
| nuclear fusion | a reaction in which two or more atomic nuclei join to form a nucleus with a larger mass. During this process, a small amount of the mass of the nuclei is transformed into a tremendous amount of energy. |
| nuclear fission | a reaction in which atomic nuclei are split into two or more nuclei with smaller masses, during which small amounts of matter are converted into large amounts of energy. |
