let’s say I have spooned some tomato paste into a glass jar, and there are all these pockets of air and I want to collect the tomato paste at the bottom of the container.

The tomato paste is viscous / thick enough that gravity is not causing it to settle anytime soon, so if I pick up and then slam the jar down, the forces can cause the paste to push down and settle into the jar.

I notice if I slam the jar on a cutting board or a hard counter-top, the tomato paste doesn’t settle very much. When I slam the jar on a rag, it seems like it settles better.

If I had to guess, I’m curtailing some of the force when hitting hard surfaces because I’m worried about the glass breaking, and I don’t like the noise so I hold back to reduce noise.

A folded-over damp rag however is softer and cushions the jar, so it doesn’t make noise and it feels like I can get away with using more force - so maybe more force = better settling?

I’m tired, so I thought I would ask why the rag trick works - but now I think I understand.

Anyway, let me know if you disagree with my reasoning here, or if I’ve overlooked something.

  • threelonmusketeers@sh.itjust.worksEnglish
    4·
    25 days ago

    Hard objects collide inelastically which transfers more force in the opposite direction after the collision. Adding a rag, towel, or pillow softens the surface and the collision is now elastic as some of the force of the jar colliding with the countertop is absorbed by the fibers of the cloth.

    Isn’t this backward? Hard objects like billiard balls collide elastically, while soft objects like clay collide inelastically.