The "h" in mgh.. Can you change it? Okay I still can't get my head around the idea of gravitational potential energy. I think that having questions answered may help my understanding. Cats usually always land on their feet, so I'll use one for my example. 1) I hold the cat ten meters off the ground I'm standing on. h is 10 meters, right? 2) I place a boulder beneath the cat, which takes up five meters. The cat is five meters above that. The h for his gravitational potential energy is half, right? He can only fall five meters now? Or is it still ten meters? 3) I put the cat back where he was, ten meters up, but now I dig a hole, straight down into the ground, ten meters deep. If I release the cat he'll fall twenty meters. Did my digging that hole give the cat additional potential energy, without even moving the cat? I'm probably misunderstanding something. Thank you for any answers and answers may prompt more questions. Thank you!