Determine the efficiency of an engine running on diesel fuel, the specific heat of combustion

Determine the efficiency of an engine running on diesel fuel, the specific heat of combustion of which is 42 MJ kg. Mass of fuel consumed 3 kg. Perfect work 35.3 MJ.

The engine efficiency can be calculated using the formula:
η = (A / Q) * 100%, where A is the work done by the engine (A = 35.3 MJ = 35.3 * 10 ^ 6 J), Q is the energy expended by the engine (Q = m * q, where m is mass of consumed diesel fuel (m = 3 kg), q is the specific heat of combustion of diesel fuel (q = 42 MJ / kg = 42 * 10 ^ 6 J / kg)).
Let’s calculate the efficiency of the engine:
η = (A / Q) * 100% = (A / (m * q)) * 100% = (35.3 * 10 ^ 6) / (3 * 42.7 * 10 ^ 6) * 100% = 0.276 * 100% = 27.6%.
Answer: The engine efficiency is 27.6%.