Simple Machines: Levers

Simple machines make our lives easier by allowing us to do tasks with less force. The mechanical advantage is the factor of which a machine multiplies the force put into it. For example, if a simple machine has a mechanical advantage of 3 it means that it made the work you did three times easier or you only had to put in 1/3 the force you would have if you didn’t have the simple machine.

A lever is an example of a simple machine that is a plank that pivots on a fulcrum. Levers allow you to lift heavier objects with less force. There are three types of levers. The difference between the three involoves where the fulcrum is located.

1^st class levers- fulcrum is between the effort and the load

                Example: see-saw, pliers, scissors

2^nd class lever- the load is between the fulcrum and the effort

                Example:  wheelbarrow, bottle opener, crowbar

3^rd class lever- the effort is between the load and the fulcrum

                Example: Tongs, tweezers

To find the mechanical advantage of a lever you must divided the distance from fulcrum to effort by the distance from fulcrum to load.

MA= distance from fulcrum to effort / distance from fulcrum to load