During the daytime, water is drawn from an upper reservoir and is run through a turbine on its way to a lower reservoir in order to produce power for a town. At night, the water is pumped back up to the upper reservoir in order to replenish the upper reservoir. Assume that the heat loss rate due to friction is 65 hp (going either up or down) and that the internal energy change is negligible. Required:
a. Find the power extracted by the turbine if the downward volume flow rate is 15,000 gallons per minute.
b. What would the upward volume flow rate have to be in order for the system to "break even"?