97. As we drill down into the rocks of Earth's crust, the temperature typically increases by 3.0°C for every 100 m of depth. Oil wells are commonly drilled to depths of 1830 m. If water is pumped into the shaft of the well, it will be heated by the hot rock at the bottom and the resulting heated steam can be used as a heat engine. Assume that the surface temperature is 20°C. (a) Using such a 1830-m well as a heat engine, what is the maximum efficiency possible? (b) If a combination of such wells is to produce a 2.5-MW power plant, how much energy will it absorb from the interior of Earth each day? SSM

97. As we drill down into the rocks of Earth's crust, the temperature typically increases by 3.0°C for every 100 m of depth. Oil wells are commonly drilled to depths of 1830 m. If water is pumped into the shaft of the well, it will be heated by the hot rock at the bottom and the resulting heated steam can be used as a heat engine. Assume that the surface temperature is 20°C. (a) Using such a 1830-m well as a heat engine, what is the maximum efficiency possible? (b) If a combination of such wells is to produce a 2.5-MW power plant, how much energy will it absorb from the interior of Earth each day? SSM