No Sweat?

Abstract

Here’s an in-class exercise that I like to do with first-year students to give them an opportunity to practice their estimation skills in the context of conservation of mass and energy, learning a tiny bit of heat-transfer along the way. And it gives me a chance to re-experience something that gives me a little shiver of wonder each time it happens - that by using reasonable estimates and applying first principles, sometimes you can derive the existence of something you see in the real world. In this case, sweat and Gatorade™ (or your favorite similar sports-drink). It is an entirely amazing thing that the laws of conservation apply not just to systems we build like potato chip factories and jet fuel refineries but also to our own bodies.