#### Simple Machine

Upon completion of this lesson, student must be able to:

• list the different types of simple machines.
• describe about levers and their working mechanism.
• define mechanical advantage, velocity ratio and efficiency.
• calculate mechanical advantage, velocity ratio and efficiency for different simple machines.

#### Simple Machine

Simple machines are those in which effort is applied at a more convenient point in a more convenient direction. This note contains information about various types of simple machine with its example, principal of simple machine.

#### Lever

A lever is a simple machine. It consists of a rigid bar which is free to turn about a fixed point called fulcrum. There are three types of lever depending upon the position of load, effort and fulcrum. This note provides us with the information about lever, its use in practical life and types of lever with examples.

#### Mechanical Advantage, Velocity Ratio and Efficiency

Mechanical advantage is defined as the ratio of resistance overcomes to the effort applied. Velocity ratio of simple machine is the ratio of distance travelled by the effort to the distance travelled by load in a machine. The efficiency of a simple machine is defined as the ratio of useful work done by machine (output work) to the total work put into the machine (input work). This note provides us with an information about mechanical advantage, velocity ratio and efficiency.