Question

A 50 kg man with 20 kg load on his head climbs up 20 steps of 0.25 m height each.The work done by the man on the block during climbing is (a) 5 J (b) 350 J (c) 1000 J (d) 3540 J

Answer 1

the normal force acting on the block due to the man is in upwards direction and since W=F.s the displacement of the man along upward direction must only be considered. now F=20*g=200N and s=20*0.25=5. thus W=F.s=200*5=1000N-m

Answer 2

Answer:

Explanation:

Mass of block (m)=20kg

Height (h)=20×0.25

=5m

As we know that,

Work done (W)=mgh

W=20×10×5

W=1000J