# Question #c49a8

##### 1 Answer

The effort force required to lift the piano is

There are two ways to arrive at this result.

**First Method:** Conservation of Energy

The first way to think about this problem is to use the fact that energy is always conserved. This means the total **work** required is the same whether we pull the piano up with or without the pulley system.

Work is defined as:

where W is work, F is force and d is distance.

The work done by the pulley system on the piano is:

So the work required to pull on the pulley system is the same:

So the effort force

**Second Method:** Mechanical Advantage

The second is by using mechanical advantage.

We can then use the mechanical advantage, to find out how much effort force was used:

The effort force is thus: