Why Does Shaking Water + Soap Increase The Pressure In The A Closed Container?

Question

This has never made sense to me. If I put a drop or two of washing-up liquid (“Dish Detergent” in US English) in a plastic food container with water, and snap on the lid, then shake the container, the lid will try to pop off on its own. Or if I do it in a screw-top container like a bottle or a jar, when I go to unscrew the lid it will act like a carbonated beverage (pop!). Why?

In: 59

Answer 1

For the same reason rubbing your hands together makes them warm – friction

You’re adding energy (kinetic energy) that turns into friction (water interacting with itself) inside a small container (closed system).