Question

A coolie X carrying a load on his head climbs up a slope and another coolie Y carrying the identical load on his head moves the same distance on a frictionless horizontal platform. Who does more work? Explain the reason.

Answer 1

When the coolie is moving on the inclined plane, there is some displacement in the vertical direction. However, when he is moving on a horizontal frictionless ground, vertical displacement is zero. So, work done in the first case is non-zero, while in the second is zero.