This lesson will introduce the three types of levers and show how to calculate the mechanical advantage of each. Learn how the application and direction of force increase efficiency with simple machines. Discover how an inclined plane helps exert a mechanical advantage, and how levers are designed around the concepts of input and output forces. Establish engineering skills at the basic level by learning the design of simple machines.
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.
1st class levers- fulcrum is between the effort and the load
Example: see-saw, pliers, scissors
2nd class lever- the load is between the fulcrum and the effort
Example: wheelbarrow, bottle opener, crowbar
3rd 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