Thermodynamics Question 2

When a gas expands adiabatically; it does work on its surroundings. But if there is no heat input to the gas, where does the energy come from to do the work?

Easy Math Editor

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Comments

It's the internal energy of the gas that it uses to do work in an adiabatic process.

Saurabh Dubey - 8 years, 1 month ago

yeah that's right.......and that's why the temperature of the gas drops after adiabatic expansion as temperature is directly proportional to internal energy of the gas.........

Rajath Krishna R - 8 years, 1 month ago

You are back!!. Was the pendulum (changing value of g) question correct?

Saurabh Dubey - 8 years, 1 month ago

@Saurabh Dubey – yeah that's it.............

Rajath Krishna R - 8 years, 1 month ago

u r correct but at inversion temp the opp happens

Himank bhalla - 8 years, 1 month ago

It is due to intramolecular force existing between molecules by 'String Theory' or 'Harmonic Oscillator'!!

Subhrodipto Basu Choudhury - 8 years, 1 month ago

from internal energy as dQ=dU+dW and dQ is 0

Tarun Bansal - 8 years, 1 month ago

If gas expands adiabatically and if it is a free expansion no work is done by the gas....free expansion means into vaccum..since question is not that clear, will answer another question also...if it expands against a piston, definitely it has to do some work and it reduces its temperature hence uses itS internal energy...

Ajith Mohan - 4 years, 3 months ago

internal energy

Dastgir Baadshah Khan Pathan - 8 years, 1 month ago

Internal pressure of gas is more than external pressure , so gas expands without any heat input.

Aditya Pratap Rana - 5 years, 8 months ago

Math	Appears as
Remember to wrap math in `\(` ... `\)` or `\[` ... `\]` to ensure proper formatting.
`2 \times 3`	$2 \times 3$
`2^{34}`	$2^{34}$
`a_{i-1}`	$a_{i-1}$
`\frac{2}{3}`	$\frac{2}{3}$
`\sqrt{2}`	$\sqrt{2}$
`\sum_{i=1}^3`	$\sum_{i=1}^3$
`\sin \theta`	$\sin \theta$
`\boxed{123}`	$\boxed{123}$