A Carnot's heat engine works between the temperatures 427°C and 27°C. What amount of heat should it consume per second to deliver mechanical work at the rate of 1.0 kW?
Show Hint
The efficiency of a Carnot engine depends on the temperatures of the hot and cold reservoirs. The heat consumed is related to the work done by the efficiency.
Step 1: Apply the Carnot engine formula.
The efficiency of a Carnot engine is \( \eta = 1 - \frac{T_2}{T_1} \), where \( T_1 = 427 + 273 = 700 \, \text{K} \) and \( T_2 = 27 + 273 = 300 \, \text{K} \).
Step 2: Calculate the heat consumed.
The mechanical work delivered is 1.0 kW, and using the relation \( W = \eta Q \), we find the heat consumed per second to be 0.417 kcal/s.
Final Answer:
\[
\boxed{0.417 \, \text{kcal/s}}
\]