For the following processes, calculate the change in internal energy of the system and determine whether the process is endothermic or exothermic:
(a) a balloon is cooled by removing 0.655 kJ of heat. It shrinks on cooling, and the atmosphere does 382 J of work on the balloon.
(b) a 100.0-g bar of gold is heated from 25°C to 50°C during which it absorbs 322 J of heat. Assume the volume of the gold bar remains constant.
