Can someone do this impossible problem?

Question

If you lift a box 60 m with a force of 120 N what is the output work? If you push the same box 200 m up a ramp to the same height with the force of 25 N what is the input work? And what is the efficiency and mechanical advantage of the ramp?

Answer 1

This problem simply requires you to follow the definition of work.. Work is the energy transfer that occurs when an object is displaced over a distance h by an external force acting in the direction of displacement.

Work = Force x Displacement

= 120N * 60m

= 7200 J

Note this energy is stored as the potential energy of the object. It is also the amount of energy that will be released if the object was allowed to fall back to ground (60m).

When you push the same block up a ramp instead of lifting it the work performed is

Work = 25N * 200m

= 5000 J

Mechanical Advantage of an inclined plane is = distance load is pushed/ height to which it gets raised.

= 200m/60m

= 3. 333

Efficiency of the ramp = 100* output energy/input energy .

Based on stated 'output energy' and 'input energy' in the problem statement this efficiency is >100%, which is physically impossible. There is likely some piece of info missing from the problem or an inaccuracy. Sorry, this one does not make sense.