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The Physics of a Rolling Rubber Band

Posted by CmdrTaco on from the thank-god-that-is-solved dept.

sciencehabit writes "Modern physics can get complicated. Sure, researchers know exactly what forces act on a ball rolling down an incline — an experiment that helped Galileo develop universal laws for movement and acceleration. But what happens when a deformable shape like a rubber band rolls around? A new study reveals that the faster it goes, the more squashed it gets (video included)."

4 of 226 comments (clear)

  1. Wow, interesting! by rotide · · Score: 4, Interesting

    If you would have asked me how it would react as it rolled faster and faster, I would have just assumed it would have gotten "rounder" and possibly larger (elastic) due to centrifugal force.

    Always amazes me how things don't always work as expected. Nature, physics, etc, are truly interesting... no, fascinating. Now if only I had a better grasp of higher level maths and wasn't a Network Engineer (data plumber).

    1. Re:Wow, interesting! by ledow · · Score: 4, Interesting

      Yes, but then people "weigh" themselves in kg's by standing on a scale that is affected by gravity.

      There are certain things that, although "visible" by ordinary people and named, don't actually exist or exist only because we *perceive* them to exist, like that optical illusion with the white triangle that isn't ACTUALLY there.

      Centrifugal force may be misnamed (i.e. not a force), it may be incorrect, but it's generally accepted that "a force" exists that has an effect on your when you're spun in a circle. Just because the direction / origin / name of that force is incorrect is no reason to tell people that they're stupid for having felt it and knowing what it is before you explain its origins.

      Back in the 60's there was an advertising campaign by scientists working on the behalf of government to target heat loss in elderly people's properties. It encouraged old people to "keep the heat in". It didn't go down well and it took them years to discover why. Eventually it was changed to "keep the cold out" and more elderly people understood that. "Cold" doesn't actually exist, it's just the absence of heat, but old people didn't think that way as easily (and who can blame them? "Shut the door, you're letting the cold in" is a common cry in my family - despite the fact that you're neither letting cold in nor arranging for some mystical "cold" entity to enter your property rather than, say, air with slightly less heat).

      There's 100% pedantic accuracy. There's complete bollocks. And somewhere in the middle is how *everybody* thinks, even if they know both extremes in detail.

  2. Re:Physics... by SpinningCone · · Score: 4, Interesting

    i agree. I always liked physics made the world look different (like "car breaks are kinetic to thermal energy converters"). never could really get into dynamics though. i remember my teacher describing the the problem of rotational inertia of a deformable object (like a jelly disk) faster you spin the more it changes shape which changes its inertia.

    props to the people out there with the knack and persistence to solve crap like that.

  3. Flying out of the drum by azmodean+1 · · Score: 3, Interesting

    I was amused by this aside:

    (The team couldn't study what happened when the two sides touched: The friction of the two sides moving in different directions sent the rubber bands flying out of the drum.)

    What? It seems pretty obvious that they could see exactly what happened when the two sides touched, "The friction of the two sides moving in different directions sent the rubber bands flying out of the drum".