1. Calculate the change in internal energy of the following system: a balloon is cooled by removing 0.651kJ of heat. It shrinks on cooling, and the atmosphere does 384J of work on the balloon.
2.Calculate the change in internal energy of the following system: a 100.0- g bar of gold is heated from 25C to 50C during which it absorbs 322J of heat. Assume the volume of the gold bar remains constant.