Question

force.
4. In which of the following cases is work being
done :
(a) A boy pushing a heavy rock
(b) A boy climbing up the stairs
(c) A coolie standing with a box on his head
(d) A girl moving on the road.
Ans. (b)..​

Answer 1

Answer :

You have already tell the answer .

(b) A boy climbing up the stairs .

Answer 2

Answer:

B and D

Explanation:

A is wrong because of no displacement

C is wrong because of right angle or 90° angle each other.