InterviewSolution
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InterviewSolution
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A block of mass 30 kg is pulled up by a rope as shown in Fig. with a constant speed by applying a force of 200 N parallel to the slope. A and B are initial and the final positions of the block. Calculate: (a) the work done by the force in moving the block A to B, (b) the potential energy gained by the block, (c) account for the difference in work done the force and the increase in potential energy of the block. |
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Answer» Correct Answer - A::B::C::D Here, m = 30kg, F = 200N, s =AB =3m, h =1.5m (a) Work done by the force in moving the block form A to B, i.e., W =F s =(200N)(3m) =60J (b) Potential energy gained by the block `E_p =mgh = (30kg)(10m//s^2)(1.5m) =450J` (c ) The difference (600J - 450 J =150J) is used in doing work against friction between the block and the slope. This energy is converted into heat. |
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