A piece of wood with mass m is still on a smooth horizontal plane. Starting from t = 0, a horizontal constant force of F is applied to the piece. At t = t, the power of F is () A. F2T2mB. F2T mC. F2T 2mD. F2T22m
From Newton's second law, we can get: F = ma, so the velocity of a = FM at t = t is v = at = FMT, so the power of F at t is: P = FV = f2tm, so choose: B
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