An engine absorbs 2000J of heat from a hot reservoir and expels 750J to a cold reservoir during each operating cycle. What is the efficiency of the engine?
efficiency= output/input= 1250/2000
if you want percent, multipy by 100
62.5%
To find the efficiency of the engine, we need to consider the formula for efficiency in terms of heat energy.
Efficiency = (Useful output energy / Input energy) x 100%
In this case, the input energy is the heat absorbed by the engine from the hot reservoir, and the useful output energy is the work done by the engine (since it expels heat to the cold reservoir).
The work done by the engine can be calculated using the First Law of Thermodynamics:
Work = Input energy - Output energy
Given that the engine absorbs 2000J of heat from the hot reservoir and expels 750J to the cold reservoir, we can calculate the work done as follows:
Work = 2000J - 750J
Work = 1250J
Now, we can substitute the values into the efficiency formula:
Efficiency = (Useful output energy / Input energy) x 100%
Efficiency = (1250J / 2000J) x 100%
Simplifying the expression:
Efficiency = (0.625) x 100%
Efficiency = 62.5%
Therefore, the efficiency of the engine is 62.5%.