The Two Balloon Experiment

A large and a small balloon are connected by a tube with taps. What happens when the taps are opened so that air can move freely between the balloons?
We might expect both balloons to end up the same size, but instead the small balloon gets smaller and the large balloon gets bigger. Air has moved from the smaller to the bigger balloon! Why does this happen?
To understand more, we placed a pressure sensor inside a balloon and measured the change in pressure as we inflated it.
The pressure increases very quickly and reaches a maximum when the balloon is still small. Then the pressure drops as we continue to inflate the balloon. So the pressure inside the small balloon is greater than the pressure inside the larger balloon. When the taps are opened, air moves from the small to the large balloon, until the pressure inside each is equal.
We experience this when we blow up a balloon: the first stage is the hardest, and once the balloon has inflated a little, it becomes much easier.

Find out more about this experiment here:

Why does stretching a balloon make it easier to inflate? Learn about viscoelasticity and why we research it here:

[burhanco]

Where can I buy the apparatus for my class please?

[on-point]

Sir why pressure become constant.I study that the pressure inside the ballon is (atmospheric pressure+ 2srface tension/radius of ballon) but in this radius is increasing then why pressure become constant it should be decrease Naa🤔🤔

[mrv]

Would a bigger or smaller balloon float in the sea faster?

[yukkwongng]

why??Because of the thickness changes?

[zoltanszucs]

A man by mouth can blow up a balloon. A balloon blows by 1 psi pressure (~0.6 atm). The max. exhale pressure of a man is 233 cm H2O in avarage, which is 0.22 atm. --> Consequently, the 1 atm scale on the graph must by a mistake! It may be at most 1 psi. Pls review