Levers

First Class Lever Fulcrum is between input force and the load Always change the direction of the input force

Number of Class 1 Levers Used : Item Number of Class 1 Levers Used see-saw                       a single class 1 lever hammer's claws                   scissors                2 class 1 levers pliers              

2nd Class Lever The load is between the fulcrum and the effort force The direction of the input force is not changed MA greater than one But the force must be exerted over a greater distance

Number of Class 2 Levers Used : Item Number of Class 2 Levers Used stapler                           a single class 2 lever bottle opener wheelbarrow nail clippers Two class 2 levers nut cracker

3rd Class Lever Input force is between the fulcrum and the load They do not change the direction of the input force MA of less than one Output force is always less than the input force The distance the output force is exerted is increased

Number of Class 3 Levers Used : Item Number of Class 3 Levers Used fishing rod                    a single class 3 lever tweezers Two class 3 levers tongs                                  

Pulley’s Pulley – moveable wheel with a groove for rope or chain to run through Cranes, construction equipment, flagpoles, cars 2 reasons we use pulleys Change a forces direction To make work easier

Single Pulley Changes the direction of the force MA= 1 Effort distance equal to resistance distance

Single Moveable Pulley Usually one stationary pulley and one moveable MA= 2 Effort distance must be twice as long as resistance distance

Block and tackle System of fixed and moveable pulley’s MA is equal to the number of strands that support the load MA = 4 Effort distance is four times longer than resistance distance

Other machines Wheel and axle- a shaft or axle connected to a larger wheel that rotate together Ex. Screwdriver, doorknob, faucets IMA = radius of wheel radius of axle

Inclined Plane Inclined plane- sloping surface that reduces the amount of force required to do work Ex. Ramps IMA= length of slope height of slope

Others Screw- inclined plane wrapped around a cylinder Ex. Jar lids, bolts, screws

Wedge Wedge- inclined plane with one or more sloping surfaces, changes the direction of the input force Ex. ax, knife,

Compound machines Compound machine- several simple machines that operate together