The incident solar readiation (energy from the sun) on a particular day is at the rate of 100 Btu/hr for each square foot of area. Consider a solar collector with an area of 50ft^2 that concentrates the energy it collects in sucha manner that a region (an enery reservoir) can be maintained at 400 F. A ssume that one half of the energy incident on the collector goes to this reservoir, which, in turn, serves as a source for a heat engine. If the temperature of the atmosphere is 70 F, what is the maximum horsepower that the system can produce.