HOTS : Work , Power & Energy

Problem 1:  A particle of mass m is displaced from a position P1 to P2 with position vectors  and  by a force .  Find the work done by the force.

Solution:   If the displacement of the particle is , the work done W by the given force  is equal to  W = F.S , when  F is a constant force.

W = F.S                                        …(1)

where



              …(2)

and
                                …(3)
Using (1), (2) and (3)

Þ  W = (c-a)b + (a-b)c + (b-c)a

Þ  W = bc – ab + ac – bc + ab – ac = 0

Net work done by the force for the given displacement is zero.

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