How can internal energy change if no heat flows in an adiabatic process?

[Arun Raja]

Homework Statement

Homework Equations

Conceptual qn

The Attempt at a Solution

work is done in gas but how can internal energy change?
there is no heat flow since it is an adiabatic process[/B]

 

[Greg Bernhardt]

Thanks for the post! Sorry you aren't generating responses at the moment. Do you have any further information, come to any new conclusions or is it possible to reword the post?

 

[Chestermiller]

From the first law, for an adiabatic process, $\Delta U=-W$, where W is the work done by the gas on the surroundings. In this situation, W is negative (the surroundings do work on the gas), so that $\Delta U$ is positive. The temperature of the gas actually rises, even though no heat was transferred to the gas. This is the same thing that happens when you compress air with a bicycle pump.

Chet