A lever is a simple machine that is used to lift or move heavy objects by applying a force at one end. There are three main types of levers:

Types of Lever

First-class levers: In a first-class lever, the effort force is applied at one end of the lever, and the load is at the other end. The fulcrum, or pivot point, is located between the effort and the load. Examples of first-class levers include a seesaw and a crowbar.

Second-class levers: In a second-class lever, the load is located between the effort and the fulcrum. The effort force is applied at one end of the lever, and the load is at the other end. Examples of second-class levers include a wheelbarrow and a nutcracker.

Third-class levers: In a third-class lever, the effort force is applied between the load and the fulcrum. The effort is at one end of the lever, and the load is at the other end. Examples of third-class levers include a baseball bat and a fishing rod.

Levers are useful for increasing the distance over which a force is applied, which allows a person to lift or move heavy objects with less effort.