STUDY GUIDE - SIMPLE MACHINES

LEVER - seesaw, shovel, crowbar, nutcracker INCLINED PLANE - ramp, stairs, ladder
· WEDGE - knife, ax WHEEL AND AXLE - bicycle wheels,
roller skates, doorknob, screwdriver SCREW - jar lid, wood screw PULLEY - flagpole rope COMPOUND MACHINES A combination of two or more simple machines. Examples - scissors, wheelbarrow, and bicycle Simple machines are tools that make work easier.    They make it easier to:
 ·      Lift a heavy weight

·      Move a heavy object

·      Push things apart

·      Hold an object together

·      Change the direction of a force -     We use the help of gravity to help us pull down in order to make an object move up.
WEDGE
Wide at one end and pointed at the other.

Helps cut or split other objects.

Examples - knife, ax.
LEVER
 A stiff bar that moves about a fixed point (fulcrum).

Used to push, pull, or lift things.

Examples - seesaw, crowbar, shovel

Crowbar
INCLINED PLANE
 A flat surface that is raised so one end is higher than the other.

Makes it easier to move heavy objects up or down.
 
Example - a ramp

WHEEL AND AXLE
A rod attached to a wheel.

Makes it easier to move or turn things.

Examples - bicycle wheels, roller skates, doorknob.

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PULLEY
A wheel that has a rope wrapped around it.

 Pulleys can be used to lift heavy objects by changing the direction or amount of the force.

 Examples-  flagpole

 

SCREW
An inclined plane wrapped around a cylinder or cone.

A common use of the screw is to hold objects together.

Examples include a jar lid and wood screw.

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COMPOUND MACHINES
A compound machine is a combination of two or more simple machines.

Examples include scissors, wheelbarrow, and bicycle