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A ball of mass 100 gm is projected upwards with velocity 10 m/s. It returns back with 6 m/s. Findwork done by air resistance. |
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Answer» W net =W mg +W air = 1 2 m(v f ^ 2 -v i ^ 2 ) Rightarrow0+W air = 1 2 *0.1[(6)^ 2 -(10)^ 2 ]=- - 3.2 From work energy thergy theorem, Wnet=Wmg + Wair resistance According to Work-Energy theorem, Wnet = change in K.E. So, Wmg = 0 and Wair = 1/2m(vf 2 - vi 2 ) =1/2×0.1(62 - 102 ) = -3.2 J. |
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