A question

This doesn't really relate to coasters all that much, but it's been bugging me. When you float in water would that be considered negative gs?

Yes, I thought of this at swim practice.

Well, g forces are still being exerted on you by gravity, I don't get how it would make you weightless.

Hard to explain

Its really the same as walking on the Earth, apart from being half submerged in it. Imagine if you will standing on a giant sponge. You still have the equivelent to 1 g pulling you towards the Earth, but you are also being pushed back up by the sponge, once its in a position where you are not moving

Short answer is no it is not zero/negative g force, just the water molecules are packed tighter together than the gas and less so than solid earth. f you found a dense enough gas i would supose you could float around like you could do in water, in fact i am going to go look for such a gas right now

Well, think of it this way. Water molecules support you in the water and that means that they are pushing back up on you.

And for a gas that would be heavy enough to support you, I believe as long as you displace more volume than your mass you would "float" on it. I'm not exactly sure how the mass and volume thing really relates, but I know something about displacement make boats float.

Edit: http://science.howstuffworks.com/question254.htm

That might help.

If you can successfully get yourself to level out underwater thats zero G's. I know that, lol..

i want to go on one of those planes that go over a huge hill and you can float. that would be fun [:p] and maybe you would get nasues[xx(]