Question

(a) A porter lifts a luggage of 10kg from the ground and puts it on his head 1.0m above the
ground. Calculate the work done by him on the luggage. [hint: take g as 10m/s2]
(b) When do we say that work done is negative?

Answer 1

Explanation:

a) W = mgh = 10*10*1 = 100 joule

b) When displacement is in direction opposite to Force exerted, work done is negative.