Engines: Crash Course Physics #24

One of the greatest inventions is the steam engine. But why? What makes it so useful? And how does it work? In this episode of Crash Course Physics, Shini talks to us about how engines work, what makes them efficient, and why they're pretty cool.

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[crashcourse]

We made quiz questions to help you review the content in this episode! Find them on the free Crash Course App!

[Aaronsutube]

I'm a mechanical engineer that's passed the thermal and fluid design PE exam, and i found this video helpful as a reminder of the basics! Thank you

[blurglide]

What a great teacher; that's a lot of thermodynamics in 10 minutes

[wokekoala]

in this show, you have to listen to EVERYTHING

[jeffrooow]

@7:25 i guess that's why it's called a "car no engine"

[Sophistry]

That diagram at 1:42 is almost exactly how your house gets electricity (unless your grid is fed by solar or wind). The power plant uses coal, natural gas, oil, nuclear fission or even garbage to create heat in what they show as the boiler. Then just replace that piston with a steam driven turbine that turns a big generator and boom, your house has glorious power.

[markholm]

The graphics have a copy editing problem. Several times, including the first, Q sub H is captioned as "input temperature" not "input heat".

[Hoosteen]

This makes a hundred times more sense than my thermo textbook. Stay awesome Shini!

[CaryDominic]

I really need a crash course mathematics...

[samuelmayerhofer]

PLEASE make CrashCourse Algebra/Geometry/Calculus.

[MBTHinSPACE]

I really like that y'all have the Giancoli book. I mean, idk if y'all use it but it was my favorite physics book and I feel an extra connection now.

[sosensualandfree]

7:42 The Little Engine That Carnot. Ha!

[toreinimene]

Nice job explaining the Carnot engine; better than my own lecturer did.
I could listen to you whole day.

[ObitoSigma]

Excellent video on engines! I'm really looking forward toward our next segment of the course: Electricity and Magnetism! Time to explore Electric Potential and Gauss' Law!

[bliamingu]

Can anyone make a summary for this video please, i really need them for an assignment

[DevletGiray]

I spent an hour this morning reading about thermodynamic engines from a Physics textbook and still had trouble understanding. Then I watch this 10 minute video and immediately understand what's going on.

[carmencitaionescu]

before my summer vacation they were exactly sincronised with what i did at school. in the vacation they we don't do, so it's perfectly sincronized now too :)) helps me a lot, as this year we have a bad teacher

[JaySmith]

Thanks! The production value is great. However:

At 05:00 you say that there is an isothermal process where heat is slowly added, but the animation shows lots of heat (Q_H) escaping. What gives?

At 05:04 You say that the isothermal expansion is 1/2 AB. Shouldn't it be the *entire* path AB?

At 05:15 you say "the temperature drops whilst the heat stays constant, which also makes the volume expand". Well this is misleading: a temperature drop would cause an isolated system volume to contract. However in a Carnot engine, the system is doing work on the atmosphere, converting internal energy into work, and dropping the temperature. It's best to say that the expansion work drops the temperature, not that a colder temperature causes an expansion.

Also, when you keep saying "the heat stays constant", shouldn't you be saying "there is no heat flow" or something equivalent?

At 05:40 you say "the heat doesn't change" but perhaps you should be saying that there is no heat flow, or the system is thermally insulated, or something else equivalent.

The way you explain it sounds as if heat is a state property, when it's not.

[renehenriksen]

Compilation Guy>>>> And I need a crash course on basic gymnastics and acrobatics that covers front- and backhandspring, front and back somersault, aerial, side-somersault and handstand.

[florbz]

this is where we left off in our first year at uni XD and I start in a few days! Perfect timing if I do say so myself!