what do you mean by conservative forces?An elevator weighing 400 kg is to lifted up at a constant velocity of 3cm s-1,what would be the minimum power of the motor to be used?
P = F * d/t = F * V = mg * V
P=400*9.8 * 0.03m/s = 118 J/s.=118 Watts
P=400*9.8 * 0.03m/s = 118 J/s.=118 Watts