DIFFERENCE BETWEEN MECHANICAL EFFICIENCY AND MECHANICAL ADVANTAGE EXPLAINED !!

We say that machines make work easier b/c they change the size or the direction of the force (input).

Mechanical advantage is a measure of how much your force is multiplied, efficiency is a measure of how much of the work you do actually goes to moving the thing you're trying to move.

Mechanical Advantage = output force

                                      Input force

If your result is :

greater than 1 = the output force is greater than the input force

(this is what you want because you don’t want to put in more force than you get out)

less than one = it requires more input force from you and does not have a mechanical advantage.

It will simply give,that how my input force is greater or lesser than output force.

On the other hand,

Mechanical Efficiency =  work output    X 100  

                                    Work input

This will give you a percentage.It simply tells how well my system 

is working.

Consider a system of pulleys used to lift a heavy load: the pulleys provide a mechanical advantage to let you lift the load more easily, but in addition to moving the load, you also have to move the rope and the pulleys.

Adding more pulleys may increase the mechanical advantage, but it also increases the amount of  extra stuff you're moving.

The more extra stuff you're moving, the less efficient the system.