Over the Summer I worked at Seabreeze as a rides operator. Being a rides operator means that I have to push buttons, deal with kids, parents, and hot weather. But there was also a lot of physics seen around the entire park, for example, there was always kids running around. Small children are quick, but most of the time it's the ones who aren't so great at keeping their balance that end up getting some help from gravity and fall straight forward. As for me, I was only allowed to operate the kiddie rides, being under 18, and one ride in particular was the Bear Trax, a kiddie roller coaster which small children or, with the exception, parents who were with children who fit the requirements could also ride as well. This ride in particular was one that went up a down-sized hill compared to the Jack Rabbit, and it'd build up its momentum with the help of the gears on the bottom of the track to pull it up. But when it gets to the top, there aren't any gears to pull it along till it gets back to where it started, so from there it's up to lack of friction and then there's an increase in velocity which sends the riders down laughing and smiling (most of the time). And at the top of the hill, there's a bunch of potential energy, and as it's going down, that potential energy will become kinetic. Thankfully the rollercoaster is enough to satisfy little kids without being too overwhelming with large hills, because larger hills means greater potential and kinetic energy, and that could lead to scared, crying children.