Plastic Frisbees, McDonald Tray, Sled, etc. You can use water to make the slide slippery.
One of the things you could do is you could put soap and water on the slide.
The things will slide
Friction is fascinating because in so many situations we try to reduce friction, but friction is a necessary force, without which everything would be impossible. Without friction we would all be flat on the floor without any methods of directing our motion. We would randomly collide with things and then continuing moving in another direction. Without friction the slide at the playground would be really fast, but you could never climb the ladder to get on it. The swings would be useless since no one could get into them. So friction is necessary for playgrounds.
china
Reduce the friction coefficient.
If there was no friction at all, you would slide down really quickly and land hard on the ground. However, the pain won't be too harsh, because the lack of friction would keep you going even if you're off the slide; you'd be sliding across and right out of the playground!
sand paper increases friction, that is to say that it is harder to slide something on sand paper than it is on a smooth surface.
A lubricant such as oil or wax, because it creates a smoother surface to slide on.
To help it slide around more easily and reduce friction.
Gravity? the strength of the floor?
A spiral slide
That is correct spelling of "slide" (to glide, or a fixture on a children's playground).