Question

When a ball of mass m is thrown upwards to a height h, the work done by the force of gravity is ______.

Options

• mgh

• −mgh

• mg

• \[mgh^2\]

Answer 1

When a ball of mass m is thrown upwards to a height h, the work done by the force of gravity is −mgh.

Explanation:

When the ball is thrown upwards, its displacement is opposite to the force of gravity, so \[\theta = 180^\circ\] and \[W = FS\cos 180^\circ = -mgh\].