8TH GRADE · HEAT ENGINES
Heat engine efficiency and environment
Energy conversion, inevitable losses and environmental consequences.
The entire theory of the lesson is collected here; you can read it without an account. In interactive mode, the same theory appears as cards, followed by questions. with checking the answer and task, and progress is saved.
Basic Concepts
Heat engine
A device that cyclically receives heat from a heater, performs work, and transfers part of the energy to the refrigerator.
It is impossible to convert all the heat received into work, so the efficiency of any real heat engine is less than one.
Heat engine efficiency
The ratio of the useful mechanical work of the engine to the energy obtained from fuel combustion.
Increasing efficiency reduces fuel consumption and the amount of excess heat for the same useful work.
Impact of heat engines
The operation of heat engines is associated with the consumption of resources, heating of the environment and emissions of combustion products.
Reducing waste, cleaning up emissions and switching to low-carbon sources reduce environmental damage.
Physical quantities
Engine efficiency
The fraction of fuel energy converted into useful mechanical work.
Unit: dimensionless quantity
Fuel energy
The amount of heat received by the working fluid from the heater.
Unit: joule ·
Lesson formulas
Heat engine efficiency
Efficiency is equal to the ratio of the useful work of the engine to the energy received from the heater.
Related formulas
The same formulas in the reference, with symbols and units.
Tasks on the topic
Statements, answer options and the walkthrough.