A weight lifter lifts a 280-N set of weights from ground level to a position over his head, a vertical distance of 1.60 m. How much work does the weight lifter do, assuming he moves the weights at constant speed?

Given :

A weight lifter lifts a 280-N set of weights from ground level to a position over his head, a vertical distance of 1.60 m.

To Find :

How much work does the weight lifter do, assuming he moves the weights at constant speed.

Solution :

We know, work done is given by :

Here, F = 280 N and d = 1.60 m

Since, weight lifer is applying and upward force and displacement is also in upward direction.

Putting all these in above equation, we get :

Therefore, work done by weight lifter 448 J.

Hence, this is the required solution.

since you're a real machine, your ama is always less than your ima, because you can never totally eliminate friction.