WHAT DO YOU KNOW ABOUT SIMPLE MACHINES

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WHAT DO YOU KNOW ABOUT SIMPLE MACHINES?
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This is an inclined plane. Ramps and staircases
are inclined planes. You use them to lift
things.
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This is a pulley. It is made of        a wheel
that usually has a groove around the outside
edge. A flag pole with a rope is a pulley.
There are pulleys in the cafeteria that pull
up the steel doors.
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This is a screw. Spiral staircases are a screw.
.
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This is a wedge. Wedges are used to break things
into parts or cuts things. Axes, forks,
knives and needles are all wedges.
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This is a wheel and axle. It uses a handle to
turn around a rod. Doorknobs, screwdrivers,
fishing rods and pencil sharpeners are wheels and
axles.
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This is a lever. It is a bar that moves on
something called a fulcrum. You can move the
fulcrum. There are three classes of levers.
fulcrum
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First class levers have the fulcrum in the
middle. A teeter-totter is a first class lever.
load
load
fulcrum
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A second class lever has the fulcrum at one end.
A wheelbarrow is a second class lever.
effort
load
fulcrum
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Third class levers have the effort in the middle.
When using a tennis racket, your shoulder is the
fulcrum.
fulcrum
load
effort
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These are third class levers.
Hammers, baseball bats, hockey sticks, golf
clubs and tennis rackets.
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All levers have a load, a fulcrum and the
force.
force
load
fulcrum
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A lever lets you 1. change the direction of
a force. 2. change the amount of force
needed to move something.
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Remember that
The force is the push or pull that moves the
lever. The object being lifted or moved by a
lever is called the force. A point where a lever
turns is the fulcrum.