What Force Allows a Balloon to Float in the Air?

[isyang94]

As the balloon rises, the force of gravity pulls on the balloon, but which force is strong enough to pull the balloon up so that it floats in the air?
thanks

 

[Dale]

Air pressure

 

[JaredJames]

You want to look at buoyancy.

http://en.wikipedia.org/wiki/Buoyancy

 

[davenn]

jarednjames,
I love the quote from Archosaur that you have started using in your signature ... that's classic :)

Dave

 

[Redbelly98]

Air pressure

Correct. More specifically, the air pressure is higher at the bottom of the balloon than at it's top, since air pressure decreases as height increases. This gives a net upward force, that we call buoyancy, which can be greater that the downward gravitational force.

 

[mathman]

Another way of looking at it is using Archimedes principle. The balloon (filled with Helium) has a lower density than air.

 

[Forestman]

Also one thing that might help you is to remember that air pressure pushes in all directions. And since the lower down one goes the greater the air pressure becomes; there is always a greater pressure from air pushing up than there is pushing down.

 

[Buckleymanor]

As the balloon rises, the force of gravity pulls on the balloon, but which force is strong enough to pull the balloon up so that it floats in the air?
thanks

Gravity allso pulls on the air around the balloon(which is air pressure) but because the air is more dense(it weighs more) than the helium in the balloon, the balloon rises.

 

[Redbelly98]

I'll just say that jarednjames scooped those of us who responded after him, myself included.

 

[Forestman]

Redbelly, I apologize, I did not see earlier that you had already wrote what I said.