Fb-2 Soap Bubble Paradox

Aim

To show that small bubbles have greater air pressure inside them than larger bubbles.

Apparatus

  • Soap bubble solution
  • Special glassware
  • Watch glass

Soap Bubble Paradox 1 Soap Bubble Paradox 2

Description

a) Principle of physics illustrated

In a soap bubble the excess pressure is related to the surface tension and radius by

A bubble is blown in each of the two pipes with the communicating tap closed. The bubbles are blown of nearly equal size. When taps B are opened the small bubble gets smaller and blows out the larger one, showing that the pressure was lareger in the smaller bubble.

Videos

Safety Notes

Soap Bubbles Paradox SOP-15