entropy

[swaha]

calculate the final temperature attained by the 2 equal masses connected by a carnot engine whose initial temperatures were T & 4T(absolute temp.) and specific heat capacities of both masses are C.

pls tell me how to approach the sum. answer is 2T.

[swansont]

How much work and how much rejected heat do you get with a Carnot engine?

[swaha]

i asked the approach. i couldnt get the work done. the temperatures are not constant.

[swansont]

For an infinitesimal time (dt) you can assume T is constant. If the efficiency were somehow 100%, all of the energy would be converted to work until the hot reservoir was as temperature T. Obviously that isn't the case, but if you can calculate an efficiency, you'll know how much the temperature decrease of the hot reservoir compares to the temp increase of the cold one, since they have equal masses and specific heat capacities. You should be able to calculate the incremental amount of energy added/lost in dt, and integrate to find the result.

[swaha]

can anybody do the sum please? for i really couldnt do it.

[swansont]

We don't do HW for people here. You have to show what you've done.

 

What is the equation relating work, heat and the temperatures?

Edited February 28, 2010 by swansont