An arrangement of two pulleys, as shown in the figure, is used to lift a 46.0-kg mass a distance of 3.20 m above the starting point. Assume the pulleys and rope are ideal and that all rope sections are essentially vertical.
a) What is the change in the potential energy of the weight when it is lifted a distance of 3.20 m?
b) How much work must be done to lift the 46.0-kg mass a distance of 3.20 m?