| A | B |
|---|
| system | a group of objects that interact or work together |
| variable | the change made in an investigation/experiment |
| constant | the part that stays the same in an investigation/experiment |
| simple machine | a machine with few or no moving parts that makes work easier |
| force | a push or pull motion needed to move a load |
| energy | the ability to do work |
| compound machine | a machine made up of two or more simple machines |
| work | what is done when a force moves a load from one place to another |
| pulley | a simple machine that is used to raise or lower a load |
| fixed pulley | a pulley that stays in place and changes the direction of the force used to lift a load |
| screw | a simple machine used for holding things together |
| thread | the inclined plane that wraps around the screw from top to tip |
| wedge | a simple machine used for splitting and cutting |
| inclined plane | a simple machine with a flat surface, raised on one end used to lift and move heavy loads with less force |
| wheel and axel | a wheel that turns on a rod called an axle: a simple machine |
| lever | a rigid bar that pivots on a fulcrum used to raise or lower a load; a simple machine |
| fulcrum | a fixed point on which a lever turns or balances |
| load | an object to be moved or lifted |
| Newton | a measurement of force |
| gravity | a force that pulls objects toward the center of Earth |
| movable pulley | a pulley that is attached to the load, 1/2 the load is supported by the fixed point on the other end of the string |
| an example of work | a force moves a load from 1 place to another |
| examples of systems | lawn mower, vacuum, car |
| difference between wedge and lever | wedge splits or cuts, lever raises/lowers load |
