A car engine burns gas at 495 K and exhausts to the air at 293 K. What is the highest possible efficiency it could have?
(NO UNIT)

Answer:
59.19%
Explanation:
Step 1:
Data obtained from the question. This include the following:
Input temperature = 495 K.
Output temperature = 293 K.
Efficiency =..?
Step 2:
Determination of the efficiency of the engine.
Efficiency is simply defined as the ratio of output to input times 100. Mathematically, it is expressed as:
Efficiency = output /input x 100
With the above formula, we can calculate the efficiency of the engine as follow:
Input temperature = 495 K.
Output temperature = 293 K.
Efficiency =..?
Efficiency = output /input x 100
Efficiency = 293/495 x 100
Efficiency = 59.19%
Therefore, the efficiency of the engine is 59.19%