Geothermal energy systems extract heat that is stored below the Earth's crust. For every 300 ft below ground, the temperature of the groundwater increases by about 5 ºF. Heat can be brought to the surface by steam or hot water to warm homes and buildings, and it also can be processed by a heat engine to produce electricity. Using the real efficiency value of 8%, calculate the output of a geothermal power plant that processes 50 lb/s of groundwater at 180 ºF and discharges it on the surface at 70 ºF.