I'm stuck on a entropy problem and have no idea how to solve it!!(adsbygoogle = window.adsbygoogle || []).push({});

Heat Q flows spontaneously from a reservoir at 394 K into a reservoir that has a lower temerature T. Because of the spontaneous flow, thirty percent of Q is rendered unavailable for work when a Carnot engine operates between the reservoir at temperature T and reservoir at 248 K. Find the temperature T.

First of all... I don't even understand the problem. Does the 394 K reservoir flow into the hot reservoir, with temperature T? And then the water flows from that reservoir through a Carnot engine into the cold reservoir, which is temperature 248 K?

I know the change in entropy equals the heat (Q) divided by the temperature (T). I also know that the work unavailable (W) equals the temp of the coldest reservoir multiplied by the change of entropy of the universe.

I would appreciate any help!! Thanks

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Change in entropy

**Physics Forums | Science Articles, Homework Help, Discussion**