Question

To lift a load of 100 kg a distance of 1 m an effort of 25 kg must be applied over an inclined plane of length 4 m. What must be done to lift the load 2 m, using the same effort?
A) Use an inclined plane of length 8 m.

B) Use an inclined plane of length 2 m. * I think this is the answer *

C) Use an inclined plane of length 10 m.

D) Use an inclined plane of length 16 m.

Answer 1

Simply it would be A

Answer 2

Work = force * distance.  We must produce twice as much energy as we are lifting the weight twice as high.  But we are not increasing the force so we must increase the length of the ramp ( distance ) instead.  The new length will be twice as great as the previous length.  So 8 metres is required. 

 25 kg * 8 m = work = 100 kg * 2 m