Consider a (X Y) kg block of iron casting at (500 X) K. It is thrown into a large lake that is at a temperature of (200 Y) K. The iron block eventually reaches thermal equilibrium with the lake water. Assuming an average specific heat of 0.45 kJ/kg. K for the iron, determine (a) the entropy change of the iron block, (b) the entropy change of the lake water, and (c) the entropy generated during the process. The specific heat of the iron is 0.45 kJ/kg. K.