| A | B |
|---|
| work | energy transferred through both force and motion |
| joule | metric unit for energy |
| foot-pound | English unit for energy |
| energy | capacity to do work |
| conservation of energy | energy cannot be created or destroyed; it may be changed to other forms or transferred to other objects |
| machine | device to make work easier |
| simple machine | machine with only one part |
| mechanical advantage | number of times a machine multiplies the input force |
| ideal system | a system without friction |
| efficiency | comparison of how much work a machine can do and how much work must be put into the machine |
| kinetic energy | energy of motion |
| potential energy | stored energy |
| gravitational potential energy | energy of position |
| elastic potential energy | energy stored by stretching, twisting, or changing the shape of an object |
| condition of elastic potential energy | object must be able to return to its original shape |
| conditions of work | object moves in the same direction as the applied force |
| chemical potential energy | energy stored or released by a chemical reaction |
| mechanical energy | sum of an object's potential and kinetic energy |
