why are jars easier to open after a beating?

Question

Why does flipping over a hard to open jar and smacking it make it easier to open? When I was younger I thought you were warping the shape of the jar…

In:

Answer 1

If you smack the bottom of the jar, when turned upside down, you usually make all the mass inside (like a jello, or jam) move fast, then hit the cover of the jar. It might loosen the cover itself. You can over jut the edge of jar cover on a floor, like i usually do with homemade tomato juice. It allows to create a tiny crac between jar and it’s cover, allowing a little air inside, decreasing pressure difference and easing opening the jar.