Types of Machines I

Lever:

A lever is a rigid bar pivotal on support known as a fulcrum or pivot. A force E (Effort) is applied at one end of the bar to overcome load L at the other end.

The distance between the fulcrum and the effort is called the effort arm while the distance between the load and fulcrum is called the load arm. 

Types of Lever:

First Class Lever:  For this type of machine, the fulcrum is between the load and the effort applied e.g. pliers, scissors, claw harmers, etc.

The fulcrum is the place where the machine pivots (or rotates). It would be observed that at both the load and effort ends, linear motion is produced.

Second Class Lever:  The load is between effort and the fulcrum.

Examples are wheelbarrows, openers, etc.

Third Class Lever: This is when the effort applied is between the load and the fulcrum e.g. nutcracker, forceps, sugar tong, forearm.