Potential Energy is difficult to define.
At the top of a slide, you have potential energy and as you slide down the slide, some of that goes into overcoming friction and some of it goes into Kinetic Energy. The latter corresponds to you sliding faster and faster.
When you get to the bottom of the slide, there is no more potential energy, thus we consider the bottom of the slide to be important. It is sometimes called the “zero point”. The concept of potential energy requires that a zero point be defined.
We could go back to the first slide and dig a five foot hole at the bottom the slide and then we could say there was more potential energy. In this second story, we would be combining two different calculations, sliding and dropping.
Interestingly though, both use the formula shown below, where m is the mass of the object, g is the acceleration caused by gravity, and h is the height of the fall (alternately, the distance traveled in the direction of travel caused by g).
P.E. = mgh
Appendix T
Vectoreverything 