If you think of how waterproof an electronic device is in relation to a free body diagram, at what force/psi is the water trying to get in at the seems of the device, for example a phone.

Question

In other words, what’s the force required at a seem or between two flat surfaces to make a device waterproof?

Also, im assuming that as you dive deeper under water, the force of the water seeping into the phone increases, but is there some sort of function/equation to predict that increase?

I understand that waterproof seals are a simple concept, but my intention is to understand all the forces at play in a mathematical way.

In: Physics

Answer 1

Water has sumface tension that sucks it into narrow structures. You can see this with a thin tube in water, like in [this pic](https://www.usgs.gov/media/images/narrower-tube-openings-allow-capillary-action-pull-water-higher ).