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प्रश्न
A force is applied on a body of mass 20 kg moving with a velocity of 40 ms−1. The body attains a velocity of 50 ms−1 in 2 seconds. Calculate the work done by the body.
उत्तर
Work done, W =`1/2` m (v22 − v12)
=`1/2xx20(50^2-40^2)`
= 9000 J
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