Why do hovercrafts lift off the ground?

Question

I am making a hovercraft for my science project this year (im in 6th grade) and i cant find why the hovercraft stays off the ground. I am using a plywood circle, a sheet of plastic and a vacuum flipped to blow. Anyway, so i want to know how it floats. PLEASE do not tell me that it is "the skirt effect" because i want to know how the skrt effect works.

Also, if you know, why does the bigger circle of plywood, the more people you can fit on it? (my dad asked me that and i am stumped)

thank you SOO much!

Answer 1

a hovercraft rides on a very small cusion of air that escapes from the bottom it "pushes" down on the ground and technically does not "lift" but float (like a boat on water) the air displaces the craft a small amount

Answer 2

The air pressure is what gives it the lift.  Get a car inner tube that's aired up, strap it to the plywood securely then mount a leaf blower to the top of the plywood and cut a tight hole for the outlet of the leaf blower. secure outlet in hole. Turn it on and you should have a hovercraft.

Answer 3

The skirt around the edge, combined with the air being blown is what makes it float. Without the skirt the air would just disperse instantly and it wouldn't float. The skirt holds the air in long enough for it to build up a positive air pressure cushion that "floats" the hovercraft. As to how you get more people with a bigger circle of plywood just draw a small circle on the ground and see how many people can stand in it. Enlarge the circle and see how many people can stand.  But putting more people on it doesn't mean you can lift them all. That depends on how stout your air supply or blower is. Good luck with the project.

Answer 4

If you haven't done your own research on this subject matter before now, then you'd better stop wasting your time on this Q&A board and get to work doing your own homework.