Statement-1: A person walking on a horizontal road with a load on his head does no work on the load against gravity.
Statement-2: No work is said to be done, it directions of force and displacement of load are perpendicular to each other.

Options

A. If both assertion and reason are true and the reason is the correct explanation of the assertion.
B. If both assertion and reason are true but reason is not the correct explanation of the assertion.
C. If assertion is true but reason is false.
D. If the assertion and reason both are false.

Answer

A

Explanation

The work done, `W = vec(F).vec(s) = F s cos theta` , when a person walk on a horizontal road with load on his head then `theta = 90^(@)`.
Hence `W = F s cos 90^(@) = 0`
Thus no work is done by the person.