- #1

- 242

- 37

- Homework Statement
- Please see the attached image.

- Relevant Equations
- ##\gamma = \frac F L##

##P = \frac F A##

The method to solving this is to equate forces along a portion of the balloon through which ##\sigma_L## acts, and another portion through which ##\sigma_t## acts. The former potion should be a circular cross section of the cylinder, while the latter will be a rectangular cross section. You will thus get the following:

I did exactly the above, except that instead of having ##2\pi r \sigma_L## and ##2x\sigma_t## on the RHS, I had ##4\pi r \sigma_L## and ##4x\sigma_t##. Am I right on this? Because I think that in either case, there are 2 surfaces (inner surface of balloon and outer surface of balloon), resulting in double the force exerted by surface tension.