Can a “miserly” system, with a concave-up entropy-energy graph, ever be in stable thermal equilibrium with another system? Explain.

ANSWER:For the concave up entropy-energy graph, the slope is negative.

And we know that,

This indicates negative temperature which is not defined generally, but at a higher level we understand negative temperature.Negative temperature is more hotter than infinite temperature.It occurs when you add more heat to a system and increase the internal...