Can a given amount of mechanical energy be converted into heat energy?

Answer 1

In any heat engine there is always some rejection of heat to the environment. Thus an internal combustion engine, as in a car, rejects heat in its exhaust gases, and also loses heat into its radiator. An aircraft jet engine rejects heat at its exhaust, it is impractical to extract more energy from this. In a power plant the steam turbine rejects heat to its condenser in order to condense the exhaust steam to water for feeding back to the boilers.

Answer 2

Yes, use a Flamethrower or Grenade.

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The first law of thermodynamics is an expression of the law of conservation of energy and identifies heat transfer as a form of energy transfer. The second law limits the efficiency of engines. While mechanical energy can always be converted entirely into heat, heat cannot be converted entirely into mechanical energy. Attempts to convert heat completely into energy always produce some waste heat.

Answer 3

Yes. In fact, sooner or later, it usually WILL be converted to heat energy. Converting energy the other way is not possible - if you have a given amount of heat energy, you might convert part of it to mechanical energy under certain circumstances, but never all of it.

Answer 4

Yes, a given amount of mechanical energy can be converted into heat energy through processes like friction or resistance. In these processes, some of the mechanical energy is lost due to the generation of heat.

Answer 5

No, most heat energy can never be converted into work. Heat is the most entropic form of energy, and therefore is limited by the second law of thermodynamics.

Answer 6

Yes, examples are steam turbines, locomotive, hydraulic turbines, etc.

Answer 7

No. Conversion of energy from one form to another always results in some wastage: no machine is 100% efficient in energy conversion.