5. Thermal pollution. A river with a water temperature Tl=20 oC is to be used as the low temperature reservoir of a large power plant, with a steam temperature of Th=500 oC. If ecological considerations limit the amount of heat that can be dumped into the river to 1500 MW, what is the largest electrical output that the plan can deliver? If improvements in hot-steam technology would permit raising Th by 100 oC, what effect would this have on the plant capacity?