InterviewSolution
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InterviewSolution
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A body of mass `6kg` is under a force which causes displacement in it given by `S= (t^(2))/(4)` maters where `t` is time . The work done by the force in `2` sec isA. `12 J`B. `9 J`C. `6 J`D. `3 J` |
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Answer» Correct Answer - D `s = (t^(2))/(4) :. Dx = (1)/(2) dt` `F = ma = (md^(2)s)/(dt^(2)) = (6d^(2))/(dt^(2)) [(t^(2))/(4)] = 3N` Now W=underset(0)overset(2)intF.dS=underset(0)overset(2)intma.dS` `underset(0)overset(2)int3xx2t xxt^(2)dt=underset(0)overset(2)int6t^(3)dt=(3)/(2)[t^(4)]_(0)^(2)=24J`. |
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