Gravity
What happens when jump up? Why do you come down? That’s because of gravity is an invisible force. It’s like super glue around the planet.
Gravity is stronger then everything on earth. I you hold a tennis ball , bowling ball or a feather , it's going down.
Boinks
If you squeeze a boink you’re creating a force. Then when you let go it will spring upland come back down.
Dropper popper when you drop a dropper popper with a ping pong ball in it the ping pong ball will shoot up in to the sky then fall to the ground.
