PHYSICS · Multi-part · Fermi University Physics · Thermal, Statistical & Complex Systems · The laws of thermodynamics · The laws of thermodynamics
Thermal Physics, Ch The second law, entropy and irreversibility
Problem
Two copper blocks, each of mass 1.00kg and specific heat capacity c=385Jkg−1K−1 taken as constant, are sealed in a rigid insulated box of negligible heat capacity. One is at 450K, the other at 200K. They are pressed together and left until they reach a common temperature. No work is done on or by the blocks and no heat enters or leaves the box.
((a)) Find the common final temperature.
((b)) Find the entropy change of each block.
((c)) Find the total entropy change.
((d)) Instead of being pressed together, the two blocks could have been joined by a reversible engine, which (as the text shows) leaves both of them at 300K. Find the work such an engine would deliver, which is the work the direct contact threw away.