| A | B |
|---|
| force | a push on an abject that can cause it to change motion |
| gravity | a force that pulls any two objects toward one another, such as you toward the center of the earth |
| inertia | the tendency of a moving object to stay in motion or a resting object to stay at rest |
| friction | a force that slows the motion of moving objects |
| energy | the ability to do work |
| potential energy | energy that an object has because of position |
| kinetic energy | energy of motion |
| mechanical energy | the kind of energy an object has because it can move or because it is moving |
| chemical energy | energy that comes from chemical changes |
| electrical energy | energy that comes from the flow of electricity |
| work | the result of a force moving an object |
| simple machine | a machine made of one or two parts |
| compound machine | a machine made of two or more simple machines |
| complex machine | a machine made of many simple and compound machines |
| inclined plane | a flat surface that is slanted which helps you to move objects across distances |
| wheel and axle | rolls and makes moving heavy objects easier across distances- as the wheel turns, it turns the rod |
| wedge | the edge of a smooth slanted surface that makes it easier to split, cut, or divide another object |
| screw | every turn of a metal screw helps you move a piece of metal through a wooden space |
| lever | a tool that pries something loose, such as a screwdriver or the claw of a hammer |
| pulley | as the wheel rotates, the cord moves in either direction- if you attach a hook to the cord, you can use the wheel's rotation to raise and lower objects |
