3) A patient rehabilitating a knee injury performs knee extension exercises while wearing a 80 N weight boot. Calculate the amount of torque about the knee joint generated by the weight boot for each of the four positions shown, given a distance (d) of 0.4 m from the knee joint center to the center of mass of the weight boot. Ignore the weight of the leg. Be sure to provide the correct direction of the torque (assume that CC is positive).