A 1.0-kg bar of copper is heated at atmospheric pressure. If its temperature increases from 20∘∘C to 50∘∘C, what is the work done by the copper on the surrounding atmosphere? Given that for Cu 3α3α= 5.1 x 10-5 / C, ρCu=8.92×103Kg/m3
A power plant operates at 32.0 percent efficiency during the summer when the sea water for cooling is at 20.0∘∘C. The plant uses 350∘∘C steam to drive turbines. Assuming that the plant’s efficiency changes in the same proportion as the ideal efficiency, what would be the plant’s efficiency in the winter, when the sea water is at 10.0∘∘C?