Answer:
Work done by the boy is 7.50 J
Explanation:
mass of the ball m = 0.5kg
height of the bookshelf h = 1.5 m
acceleration due to gravity = 10 m/s²
work done = ?
Workdone = force × distance
In this case Weight = Force
Workdone = mgh
= 0.5 × 10 × 1.5
= 7.50 J