Question 10.3 (P4/P5) Show that 3 + 11 + 19 +· · ·+ (8n−5) = 4n 2 −n. (Your first step should be to rewrite the Left Hand Side of the equation using summation notation.)

A47.2 g block of copper whose temperature is 480 k is placed in an insulating box with a 91.8 g block of lead whose temperature is 200 k. (a) what is the equilibrium temperature of the two-block system? (b) what is the change in the internal energy of the two-block system between the initial state and the equilibrium state? (c) what is the change in the entropy of the two-block system? the heat capacities of copper and lead are 386 j/kg·k and 128 j/kg·k, respectively.