A girl having mass of 35 kg sits on a trolley of mass 5 kg. The trolley is given an initial velocity of 4 m s–1 by applying a force. The trolley comes to rest after traversing a distance of 16 m.

(a) How much work is done on the trolley?


(b) How much work is done by the girl?


Mass of the girl = 35 kg


Mass of trolley = 5kg


Initial velocity = 4m/s


Final velocity = 0m/s


Distance covered = 16m


Using the equation of motion,



Now Force = mass x acceleration,



(A) Work done on the trolley = 20 N ×16 m = 320 J


(B) Work done by the girl = 0 J.


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