Question

answer Quickly..9 th question

Answer 1

a)the boy has applied a force and the bag has moved through a height . so there is a work done
b)the girl is applying a force but the stone doesn't seem to move so there is no work as it has not moved

Answer 2

Hi there ,
We say that work is done when-
i)a force acts on a body
ii)the body is displaced along a distance in the SAME direction of the force.


Here in the first case (i) ,

The boy is lifting the body upwards.
Hence force is acting on the body.
Second , the suitcase is getting displaced from its original position and along the SAME DIRECTION of the force.

Hence work done is done
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In the second case (ii) ,
Force is being applied , but displacement is zero.

Work done = Force x Displacement

Here , when displacement is zero , work done would be also zero.