Ropes and Pulleys. Pulleys Pulleys only change the direction of the tension force not the magnitude.
Levers and Pulleys
description
Transcript of Levers and Pulleys
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 houseLifting a carBuilding the pyramidsHandicap rampsPaper cuttersWheels 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 MachinesLeverPulleyWheel and axle Inclined plane WedgeScrew
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 loadExamples 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 armExamples 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 axisExamples 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