Question

the temperature of a heat engine is 500 k. some of the heat generated by the engine flows to the surroundings, which are at a temperature of 125 k. the efficiency of the engine is %

Explanation:

Step1: Recall efficiency formula

$\eta = 1-\frac{T_{c}}{T_{h}}$

Step2: Identify temperatures

$T_{h}=500$ K, $T_{c}=125$ K

Step3: Calculate efficiency

$\eta = 1-\frac{125}{500}=1 - 0.25 = 0.75$

Step4: Convert to percentage

$0.75\times100 = 75\%$

Answer:

75