Levers and PulleysNot so simple machines!
Just think…. Could you lift your science
teacher in the air?
Keep Thinking…..(This means you don’t have to write this!!)
Building a house
Lifting a car
Building the pyramids
Handicap ramps
Paper cutters
Wheels on a car What do all of these have in common?
They are use simple machines!
Important DefinitionsMachine- device for doing work
Complex machines have motors, simple machines do not
Effort- the amount of force applied to a machine Effort is measured in Newtons (N)
Types of Simple MachinesLever
Pulley
Wheel and axle
Inclined plane
Wedge
Screw
Just Read…Simple machines have been used for thousands of years. They were even used to help build the pyramids!
LeversThe most simple and most common simple machine.
3 Parts of a lever
Class 1 Levers
Class 1 LeversThe fulcrum is located somewhere between the
effort and the load
Examples include: The claw of a hammer crowbar
Double Class 1 LeversTwo levers working together form a double
lever
Examples Include: Scissors Tin snips
Class 2 Levers
Class 2 LeversHas a fulcrum at one end of the lever arm
Examples include: Paper cutter Wheelbarrow
Class 3 Levers
Class 3 Levers In a class 3 lever, the fulcrum is at one end,
and the effort is applies between the fulcrum and the load
Examples include: Baseball bat Fishing pole Catapult
Wheel and Axle
Wheel and Axle
Wheel and AxleCan be an actual wheel and axle OR a bar that
rotates around an axis
Examples include: Steering wheel A wrench turning a bolt (see levers and pulleys
book page 7) Windlass (crank used to raise a bucket, see page
8) Handle of a faucet (page 8)
The Inclined Plane
The Inclined Plane
The Inclined PlaneA sloped, flat surface, or ramp
One-part simple machine that does not move
Pulleys
PulleysA pulley is a wheel that is free to turn on an
axle The wheel is called a sheave A pulley is considered to be a variation of the lever Pulleys can be fixed or movable
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