Force and Motion

Unit 2

Force

A push or a pull

Inclined plane

A simple machine that is a flat surface with one end higher than the other

Speed

The distance an object moves in a given amount of time

Motion

A change in the position of an object as it is moving

Friction

A force that slows down a moving object when it rubs against another object

Magnet

An object that pulls objects made from iron toward it

Pole

One of the two ends of a magnet where the pull is the strongest

Attract

To pull toward- unlike poles on a magnet attract each other

Repel

To push away-like poles on a magnet repel each other

Magnetic Field

All of the invisible magnetic forces around a magnet

Gravity

A force that attracts objects to each other. The force of gravity holds you to Earth.

Simple Machine

A machine that makes work easier

Has few or no moving parts

Wedge

A simple machine made of two inclined planes joined together

Example: an ax

Lever

A simple machine made of a bar that moves on a fixed point

Example: a crowbar

Pulley

A simple machine made up of a wheel with a rope around it

Lifts heavy objects

Wheel and Axle

A simple machine made up of a wheel with a rod going through the center

Example: skates, cars

Screw

A simple machine with ridges or threads that wrap around a rod

Examples: a drill