Q. A pulley system has an efficiency of 87.5 percent. How much of the rope must be pulled in if a force of 648 N is is needed to lfit a 150 kg desk 2.46 m ?
Q. A particle moves along the x axis under the influence of a variable force F(x) = 6.6x2 + 3.3x where the force is measured in Newtons and the distance in meters. What is the potential energy associated with this force at x = 4.0 ? Assume that U(x) = 0 at x = 0 .