If I filled a basketball with helium, how much weight could it lift off the ground.?

Question

It would only have to clear the ground by an inch.

Answer 1

None whatsoever.

A basketball is 8 inch in diameter, this means it internal volume is 4.39 l. That means .00275 oz of helium inside (assuming 1 atmosphere of pressure) instead of 0.2 oz of air.
The ball itself weight 21 oz or so. That is not the .0.17 oz saved by having helium instead of air in it that will make the ball able to float in the air.
Sorry.

Answer 2

If you filled a standard basketball with helium, it could not lift itself off the ground.

Helium provides lift by being lighter than air. The amount of lift it provides comes from the amount of air displaced. So, the lift of any amount of helium is approximately the volume involved times the difference in mass of helium and air.

Even if the helium had no mass, the most lift you get is the weight of that much air. So, if the rubber (leather whatever) shell of a basketball weighs more than a basketball sized chunk of normal air (which it does), then a helium filled basketball will not float. In fact, it would only weigh a little less than an air filled ball. Probably not enough for most people to tell the difference holding a helium filled basketball.

Answer 3

The amount of weight it coule lift would be equal to:
=== the DIFFERENCE between the weight of the helium in the ball and the weight of the same volume of air
==== LESS the weight of the b-ball's rubber shell (it's got to lift that, too)

Probably not much weight - and maybe none at all. You need to know the difference in density of He and air (N2 and O2). Then multiply this difference by the volume of a basketball - this is the 'bouyant force', but you also need to subtract the wright of the empty rubber bball shell. This shell might be too heavy - if its weight is greater than the difference of the air vollumes, the ball will never lift off.

The math is simple but keep careful track fo the units (g/cc, cubic inches, etc),

Also - pressurizing the ball (putting in more He) makes the problem WORSE, not better - since you are just putting more weight into the ball.

Answer 4

For fun try this...attach some helium baloons to a basketball and keep going until it floats (you will need LOTS of baloons and a TANK full of helium), that's the volume of helium it would take and it won't fit into a basketball, sorry.