If you had a bowling ball sitting statically on top of a perfect rectangluar porcelain tooth, and the bowling ball caused a crack in the porcelain tooth (hairline fracture), but then you immediately took the bowling ball off the tooth... wouldn't there be no work done since the bowling ball didn't move downward any distance from the force of gravity? The tooth is at the same level (height) if it has a crack in it, isn't it? Work requires force over a distance. It seems cracking the tooth is missing the distance part of work. My theory in this case is that a small movement did occur (in the tooth), but I'm skeptical of the bowling ball movement (which seems to be zero). The crack would virtually not cause the bowling ball to change height, but the tooth would move a hairline sideways. The tooth is still at the exact same level height wise, but the tooth is a hairline wider due to the space in the new crack. The tooth doesn't split into two pieces and break apart completely, it just has a hairline crack. This is not a homework question, I'm simply doing a thought experiment to see if there can be Work done without any distance covered. Another example would be a hydraulic cylinder that is plugged, you put a lot of force on the piston and the hydraulic cylinder develops a hairline crack in it - but no fluid leaks out, the hairline crack is such a small crack that the fluid remains in the exact same position as it was before the hairline crack. The fluid is so thick that it doesn't seep through the crack at all. The pressure caused the crack since it is a closed system that is plugged up. Again in this case my theory is that a small movement must have occurred - some of the fluid must have budged just a tiny bit, to fill in the tiny new space made available by the hairline crack. If the crack was small enough, it would seem that it would have no effect on the distance the piston moved - because the fluid has nowhere new to go - it can't move any fluid into the crack, and the cylinder remains exactly the same shape and size, it just has a tiny crack in it. The hairline crack may cause the volume of the cylinder to increase just a hairline due to expansion, but I think you could have a hairline crack that is so unnoticeable and small that the cylinder maintains the same volume. If you absolutely must move the piston in order to do work, then it must be a hairline distance via a massive amount of force.