What are levers
A lever is a force multiplier and speed multiplier. A lever is a long rigid object and a pivot or a fulcrum about which it rotates. e.g. crowbar, hammer (taking out a nail), handle, catapult. The way a lever operates depends upon the position of the effort, load and fulcrum. There are three different kinds of levers:
First-class lever, Second - class lever and a third - class lever.
First-class lever, Second - class lever and a third - class lever.
Principle of Levers
Effort x distance = load x distance
First - class lever
First class levers have the fulcrum positioned between the effort and the load forces.Kind of like a balancing beam. e.g pliers, tin snips, hedge cutters, scissors, trolleys.
Second - class levers
If the load is positioned between the fulcrum and the effort, then the lever is called a second - class lever. This also acts as a force multiplier. e.g wheelbarrow, bottle opener, paper guillotines and nutcrackers.
Third - class levers
The effort is positioned between the fulcrum and the load, then the lever is called a third - class lever. The broom acts as a third - class lever because, it traded and increase in force for an increase in speed. e.g broom, tennis racquet, cricket bats, golf clubs, tweezers and tongs.
How to find the mechanical advantage of a lever
There are two ways to determine the mechanical advantage of a lever.
- Mechanical Advantage=distance from effort to fulcrum/distance from fulcrum to load
- Mechanical Advantage=load/effort