Awoman uses a pulley and a rope to raise a 12 kg weight to a height of 2 m . part a if it takes 4 s to do this, about how much power is she supplying?

To solve this problem it is necessary to apply the concepts related to work and power.

Remember that work is defined as the force applied on a body - or exerted by it - to travel a certain distance, and that the power is that energy mentioned to perform that activity in a given instance of time.

Mathematically work is defined as

Where

d = Distance

At this case the acceleration is the same that gravitational acceleration

At the same time we have that power is defined as

Replacing our values we have that the Work done was

Now substituting this value at the Power equation we have

Therefore the power that she is supplying is 100W.