Delilah loves our trampoline(s). Every day is leg day. It’s one of the best investments we’ve made (particularly the mesh safety surround). One thing that helped us learn more about planetary (among other) physics is use of orbits around the “sun”. Sometimes the sun is a person, other times a bowling ball, but in any case, I had originally moved the trampoline around the yard with a bubble level in the middle. I did this quite a bit until I found a spot where it could sit pretty darn level.
Then, so that everything doesn’t spin out into the grass, I snaked our rubber garden hose around the perimeter to act as a ball bumper keeping things in. Finally, I added an assortment of balls including plastic, rubber, billiard, and one big bowling ball.
The trampoline is a great way to explain how a large mass will warp spacetime and create what can best be envisioned as a bend in which other mass will be drawn to through gravity. Depending on its orbit & color, Del can “identify” planets as the orbit (& eventually crash into) the “sun”.