Heat Engine

A heat engine makes use of the natural tendency of heat to flow from hot to cold, and converts some of that heat to work. The efficiency of a heat engine describes what fraction of that input heat can be converted to work.

[@Benjamin-rz9qn]

My name is Ben Jamin, and I approve this message.

[@MD-bj1uo]

Can you please explain why here you write -w = nR( Th-Tc) lnV2/V1.. and not (Tc-Th) as explained in the previous video for the Carnot cycle? Is it because you switched the signs?

[@PhysicalChemistry]

Yes. In the previous video, we had w = n R (Tc - Th) ln V₂/V₁ In this video, the numerator is −w, with a negative sign. I could have written that as −w = −n R (Tc - Th) ln V₂/V₁ But instead of adding the negative sign out front, I just switched the order of the two temperatures, using this instead: −w = n R (Th - Tc) ln V₂/V₁

[@RSS18]

Great👍

[@eulersfollower7140]

The system is insulated ,so the Q_h given as heat will be used in doing work ,but how does it expel heat as Q_c,if all the heat becomes work ?

[@PhysicalChemistry]

The adiabatic steps are insulated, but the isothermal steps are not. So heat does transfer to/from the environment in those steps. See the preceding video on the Carnot cycle for more details: kzbin.info/www/bejne/qavcd4Srhc6Db9U I love your username, btw!