Engine efficiency is calculated by dividing the work output of the engine by the heat input. In this case, it would be 0.120 kJ of work divided by 0.490 kJ of heat, resulting in an efficiency of approximately 24.5%.
The work output of an engine refers to the amount of energy or power that is produced by the engine. It is measured in units of joules (J) or kilojoules (kJ).
The heat input of an engine refers to the amount of energy or heat that is used to power the engine. It is also measured in units of joules (J) or kilojoules (kJ).
There are several factors that can affect engine efficiency, including the type of fuel being used, the design and condition of the engine, and the operating conditions (such as temperature and pressure). Additionally, the type of engine (e.g. gasoline vs diesel) and the load on the engine can also impact efficiency.
Engine efficiency can be improved by regularly maintaining and tuning the engine, using high-quality fuel, and ensuring proper operating conditions. Additionally, new technologies and designs, such as hybrid or electric engines, can also greatly improve engine efficiency.