Too good to be true?

[Diver]

Then the air above it falls around the balloon and settles under it. The balloon's 'desire' to fall is weaker. More and more air falls around and settles under it, pushing the balloon up in the process.

Helium balloons don't float up, they are suspended on fallen air.

I bet that post goes down like a lead balloon

[scooterscot]

Then the air above it falls around the balloon and settles under it. The balloon's 'desire' to fall is weaker. More and more air falls around and settles under it, pushing the balloon up in the process.

Helium balloons don't float up, they are suspended on fallen air.

The question is does it fall or is it pulled?

Perhaps the density of the air below is only matched the mass volume of the inflated balloon.

[Diver]

It's all coz of that "Eureka!" chappie in his bath... weight of volume displaced is greater than the weight of the thing doing the displacing.

Finally

[TimberWolf]

The question is does it fall or is it pulled?

Ah, that old chesnut

When you 'push' out your arm, are you pushing or pulling? (The triceps contract to push out the forearm, in fact muscles only 'pull' [or push if you is that way inclined]).

[TimberWolf]

Finally

Perhaps more interestingly, buoyancy is a consequence of differences in pressure acting on the surfaces of the body, and the pressure increases with depth. We are buoyed in air too.

[TimberWolf]

A gravy train would be the most eco-friendly method of transport?

Just ask anyone here, they may not understand Newtons laws but they know how to get on the gravy train

[Diver]

Perhaps more interestingly, buoyancy is a consequence of differences in pressure acting on the surfaces of the body, and the pressure increases with depth. We are buoyed in air too.

Er! Diver <----------

My life depends on my complete understanding of the principles.

[TimberWolf]

Er! Diver <----------

My life depends on my complete understanding of the principles.

Okay, show that Archimedes principle is a consequence of the pressure differences on the surface of a submerged body. Extra marks will be awarded for using the words surface, cross-sectional or wetted area.

[scooterscot]

We are buoyed in air too.

Oh no we're not.

The pressure required to keep our feet off the ground would be quite unbearable not to mention messy.

It's the electromagnetic force that's keeps us from becoming part of the ground.

[scooterscot]

pressure increases with depth.

I don't mean to be picky but pressure is also proportional to temperature.