How much work is needed to blow a soap bubble of radius 3.5 cm from a solution of surface tension…
Contributed by StemPy LabTry it on paper first. A hint, the key idea and the worked solution are here when you need them.
How much work is needed to blow a soap bubble of radius from a solution of surface tension ? What is the excess pressure inside it?
Need a reminder? The key ideaShow
Surface tension is force per unit length, or energy per unit area of surface, in . A film has two surfaces. Excess pressure: inside a drop or an air bubble in a liquid, inside a soap bubble.
The worked solution
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Step 1. Work. .
Step 2. Pressure. .
Answer: ; .
Watch out. Count both surfaces in the work and in the pressure.
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