Simple Machines

Simple MachinesThere are six types of simple machinesLeverPulleyScrewWheel and AxleInclined planeWedgeLeverA lever is a rigid object that pivots or rotates on a fixed point.The fixed point is called a fulcrum.

First Class LeversIn first class levers the input (the force you put in) is on the opposite end of the output (the work the lever does).Examples of this are see saws, scissors and pliers

Second Class LeversSecond class levers have the fulcrum on one end with the input (the force you put in) on the other end and the output (the work the machine does) in the middle.Some examples are wheel barrows, nut crackers and doors.

Third Class LeversThird class levers have the fulcrum on one end and the output (the work the machine does) on the other end with the input (the force you put in) in the middle.Examples of third class levers are baseball bats, hockey sticks, shovels and your arm.

PulleysPulleys are made up of a grooved wheel and some sort of rope or cable. Examples of a pulley are the pulley at the top of a flagpole, a construction crane and the pulleys that make weight machines work.

Three Types of Pulleys

Block and TackleScrewA screw is an inclined plane wrapped around a cylinder.Try this take out a piece of paper and fold it so it makes a large triangle. Start at the top of your writing utensil and wrap the triangle around it. Notice what you get.

Wheel and AxleA wheel and axle is a simple machine made from two circular objects fastened (attached) together that rotate.

Inclined PlaneAn inclined plane is a simple machine made of a sloped surface. A ramp and stairs are examples of inclined planes.

WedgeA wedge is actually 2 inclined planes put back to back. A wedge moves and a regular inclined plane does not. Examples of wedges are axes, your teeth, knives etc.