An iron block of unknown mass at 85°C is dropped into an insulated tank that contains 100 L of water at 20°C. At the same time, a paddle wheel driven by a 200-W motor is activated to stir the water. It is observed that thermal equilibrium is established after 20 min with a final temperature of 24°C. Assuming the surroundings to be at 20°C, determine
(a) The mass of the iron block and
(b) The exergy destroyed during this process.

Transcribed Image Text:

Water Iron 85℃ 100 L 20°C 200 W