Trick Question: Two Identical Balls, Different Heat Responses

The question was about two identical balls except that one’s sitting on the ground and one’s being hung by a string. And then they both have an increase in energy of 100 joules and which one gets hotter? Which one has a greater increase in temperature? And it’s kind of a trick, I’ll tell you the answer. Because if we think about the work energy principle that says that the work done, which would be the energy going in, would be the change in energy of the system. So that could be two kinds of energy. Thermal energy plus gravitational potential energy. And there is the trick right there. So in this case, when this is increased in temperature, it’s going to expand and that’s going to raise the center of mass. So this one’s going to have an increase in gravitational potential energy so that you don’t get as much increase in thermal energy. This one, if it’s hanging from the top, would actually increase in size and the potential energy would decrease because the center mass would go down. So this one would have more thermal energy increase and this one would have less. So this would be a higher temperature. I know it’s a trick question. I said it was a trick. So you can’t get mad.