Respuesta :

Answer:

Explanation:

Be careful how you answer this. Heat is not a useful by product of work. It does not add to the efficiency of an engine.

The actual work done by the engine is 45 J - 31 J = 14 J

The efficiency is = Useful Work / Total Work in * 100%

Useful Work = 14 J

Total Work = 45 J

Efficiency = (14/45) * 100

Efficiency = 31.1 % efficient.