Two rigid boxes containing different ideal gases are placed on a table. Box
A contains one mole of nitrogen at temperature
T0, while box
B contains one mole of helium at temperature
(7/3)T0. The boxes are then put into thermal contact with each other, and heat flows between them until the gases reach a common final temperature (Ignore the heat capacity of boxes). Then, the final temperature of the gases,
Tf, in terms of/
T0 is :