# simple machines

## 25 terms

### gravity

force that pulls 2 things together

push or pull

### inertia

causes objects at rest to remain at rest and objects in motion to remain in motion

### energy

the ability to do work

### work

when force is used to move an object, only occurs when something moves

object being lifted or moved

### effort force

amount of force needed to move something

### simple machines

one of six objects that help you do work includes levers, pulleys, wheels and axles, inclined planes, wedge, screw, and gears

### efficiency

the amount of useful work a machine puts out compared to the amount of work that is put in

### friction

the force that acts against objects in motion when one surface touches another

### speed

the distance traveled in a certain amount of time

### pulley

can be fixed or moveable, can change the direction of force or decrease the effort force, the more you use the less force you need.

### inclined plane

allows you to push or pull instead of lift, a ramp is an example.

### lever

consists of 2 parts a bar and fulcrum, there are 3 types, makes it easier to lift things.

### gears

can work with a wheel and axle, larger ones are easier to turn, can change the direction and amount of force

### wheel and axle

has 2 parts, one part is a bar that passes through the other part, the bar turns a small force into a larger force

### wedge

pushes things apart by changing the direction of the force

### screw

a spiral inclined plane that increase force to move deep inside something.