Simple Machines Simple Machines device that makes work

Simple Machines

Simple Machines • device that makes work easier • changes the size or direction of the force • Does Not decrease the overall amount of work to be done

Simple Machines(cont. ) • multiplies effort force • come in many shapes and forms; but there are only 6 types

A machine requires two types of work: work input--the work effort supplied by the person --also called effort force work output--the work done by the machine --also called output force, resistance or load

Levers • machine consisting of a bar that pivots around a fixed point called a fulcrum • three types of levers based on the location of the fulcrum, load and input force or effort F— 1 st fulcrum in middle (between) O— 2 nd output force in middle E— 3 rd effort force in middle

st 1 Class Lever Fulcrum in the middle

2 nd Class Lever Output force in the middle

3 rd Class Lever Effort force in the middle

Pulley • consists of a grooved wheel that holds a rope or cable • load is attached to one end of the rope • input force is applied to the other end of the rope • 3 types: Fixed Moveable Compound/Block & Tackle

Fixed Pulley A pulley that is attached to something to hold it steady makes work easier by changing the direction of the force

Moveable Pulley one end of the rope is attached, but the wheel is free to move load is supported by 2 sections of rope; rope ½ the force is needed versus a fixed pulley

Compound or Block & Tackle a fixed & movable pulley has highest mechanical advantage

Inclined Plane has a flat surface raised on one end; end a ramp force longer ramp has a greater mechanical advantage

Wedge two inclined planes join together to make a sharp edge used to split or lift objects

Wheel & Axle consists of: shaft, shaft called the axle, axle inserted through the middle of a wheel force applied to the wheel, wheel is magnified when transferred to the axle

Screw an inclined plane that is wrapped around a cylinder ridges on the screw are called threads greater the number of threads the easier it is to turn; greater the M. A.