Question

A man weighing 80 kg carries a stone of 20 kg
to the top of the building 30 m high. The work
done by him is (g = 9.8 m/s)
(A) 80 J
(B) 100 J
(C) 980 J
(D) 29,400 J​

Answer 1

Answer:

D

option

Explanation:

Work done = mgh

As it is on some height

w = 100 x 9.8 x 30

w = 29,400 J

Answer 2

Answer:

W = F x d

F = m x a

m = 80 + 20 = 100kg

F = 100 x 9.8 = 980 N

W = 980 x 30 = 29400 J