# Energy minimization

1. Jul 8, 2008

### ice109

let's suppose i have two differently pressurized balloons and i push them together. how can i predict what that contact surface will look like? to make this simpler let's say i have two disjoint hemispheres which contain a pressurized gas each, again at different pressures, and i push them together. how do i predict what that contact surface looks like?

2. Jul 9, 2008

anyone?

3. Jul 9, 2008

### Cvan

Its an optimization problem. Sounds like it would be a fun problem to solve, but incredibly annoying to set up. You would have to take into account the balloons' respective elasticity, whether or not the gasses are equally as compressible, how the balloons themselves deform--

And remember, if you push two spheres together, you're exerting a force to push them together, so the sphere deforms on both sides.

You could guess however, depending on the size and pressures involved of these balloons, and assuming that they're spheres--that intuitively the first thing that comes to mind is that the contact surface will be shaped like a circle with the center pushed towards the LOWER pressure balloon (so it looks like a bowl on its side--bottom facing the lower pressure side.

4. Jul 9, 2008

### vipulsilwal

experiment is needed to be done for this

air inside balloons is at higher pressure...this outward force is balanced by force due to elasticity of it and atomspheric pressure ...
when another balloon comes in contact with other balloon, situation changes..outward force due to that is to be considered..
one balloon might look a little flat and other a little bulging out..