Simple Machines- William

SIMPLE MACHINES • Simple machines make work easier

for us by allowing us to push or pull over increased distances

The pulley • The pulley is a simple machine that uses grooved wheels and a rope to raise, lower or move a load.

LEVERS • There are three classes of levers

which represents variations in the location of the fulcrum and input and output forces.

FIRST CLASS LEVER • First class lever is a lever in which

the fulcrum is located between the input effort and the output load.

SECOND CLASS LEVER • In a second class lever the input

effort is located at the end of the bar and the fulcrum is located at the other end of the bar, opposite to the input, with the output load at a point between these two forces.

THIRD CLASS LEVER • For this class of levers, the input

effort is higher than the output load, which is different from second class levers and some first class levers. However, the distance moved by the resistance load is greater than the distance moved by the effort.

WEDGE • A wedge is an object with at least

one slanting side ending in a sharp edge, which cuts metal apart.

INCLINED PLANE • Inclined plane is a slanting surface

connecting a lower level to a higher level

WHEEL AND AXLE • A wheel with a rod called an axle, through it’s center lifts or moves loads.

SCREW • A screw is an inclined plane wrapped around a pole which holds things together or lifts materials.