(Required source temperature for a specified performance)
An ideal heat engine is designed so that 40 of the heat it absorbs is converted into useful work. The engine will discharge waste heat to a cooling pond that remains at 27∘C throughout the year.
(a) Determine the minimum temperature, in kelvin, that the hot reservoir must have for the engine to meet its design specification.
(b) Express the temperature obtained in part (a) in degrees Celsius.
(c) If the actual hot reservoir temperature is raised further by 100∘C, calculate the new maximum efficiency attainable.