Question

A man lifts 100 boxes each of mass 15 g to a height of 1.5 m. Find the work done by the man against gravity

Answer 1

total mass = 100*15\1000
= 1.5 kg

g [ acceleration due to gravity ] = 9.8m\s^2

•°• force = mg
= 1.5 * 9.8
= 14.7 N

•°• work done = force * displacement [ height ]
= 14.7 * 1.5
= 22.05 Joule