On Easter, I had the pleasure of celebrating with a friends family (because all of my family lives in a land far, far away). Her cousins really liked playing on the tire swing they have in their yard. I don't blame them, tire swings are pretty swanky. For some reason they really liked when I pushed them. Maybe it was just because I was a new person that isn't family. Or, maybe it's because of physics. My friend and I, being the oldest kids there, ended up supervising after we ate Easter lunch. When my friend pushed them, they seemed to enjoy it but they really did when I pushed them. That's all because of potential energy and it's transformation into kinetic energy. Being 6'2" (an entire foot taller than my friend) I was able to pull them to a much higher height before letting them go. This means they had a larger potential energy as P=mgh. The height they could reach with me pulling them was much larger. Due to the conservation of energy the kinetic energy would also be much greater with me pulling them allowing to reach a larger velocity, K= .5mv^2. And when you're little, faster means more fun.