Question

A) Four men lift a 300kg box to a height of one meter and hold it without raising or lowering it. a) How much work is done by the men in lifting the box?

b) How much work they do in just holding it?

c) Why do they get tired while holding?​

Answer 1

Answer:

a) 3000 Nm b) 0 c) expenditure of energy

Step-by-step explanation:

a) work done = force x displacement

                      =mg x displacement = mg x s

                      = 300kg x 10m/s2 x 1m

                      = 3000 Nm

b) 0 as - while they were just holding it, no displacement was caused. hence,

 work done = force x displacement = force x 0 = 0

c) when work is done, energy is spent. since energy is spent, they get tired.