Work Energy And Power Question 231

Question: A man starts walking from a point on the surface of earth (assumed smooth) and reaches diagonally opposite point. What is the work done by him?

Options:

A) Zero

B) Positive

C) Negative

D) Nothing can be said

Show Answer

Answer:

Correct Answer: A

Solution:

[a] As surface is smooth so work done against friction is zero. Also the displacement and force of gravity are perpendicular so work done against gravity is zero.