• Victor@lemmy.world
    link
    fedilink
    English
    arrow-up
    23
    ·
    9 months ago

    A rotating spheroid will oblate when its centrifugal force generates enough inertia to slightly flatten it out into a more irregular, elliptical shape.

    I didn’t know inertia could be generated. I thought mass just had inertia. Could someone explain? Are they talking out of their ass or is that statement actually accurate?

    • mlg@lemmy.world
      link
      fedilink
      English
      arrow-up
      12
      ·
      edit-2
      9 months ago

      I think whoever wrote it just used the wrong word because yes inertia is dependent on mass, not momentum

      Okay I actually decided to check and I think it just a poorly written explanation of rotational inertia

      A rotating spheroid will oblate when its centrifugal force generates enough inertia angular momentum to slightly flatten it out into a more irregular, elliptical shape.

      If the shape also changes, this would mean distribution of that mass relative to the axis of rotation would also have changed, which if I’m reading this right, affects rotational inertia.

    • ShaunaTheDead@fedia.io
      link
      fedilink
      arrow-up
      6
      ·
      9 months ago

      Inertia is the tendency of objects in motion to stay in motion, and objects at rest to stay at rest, unless a force causes its speed or direction to change. from Wikipedia

      So they’re kind of just saying that once it picks up enough rotational speed.

      • Victor@lemmy.world
        link
        fedilink
        English
        arrow-up
        3
        ·
        9 months ago

        Thank you! I appreciate it. I had a hunch they were sloppy with the term “inertia”, and this confirms it for me, assuming I’m understanding it correctly.

    • prashanthvsdvn@lemmy.world
      link
      fedilink
      English
      arrow-up
      6
      arrow-down
      1
      ·
      9 months ago

      They are talking about Moment of Inertia. Inertia wrt to rotation changes with how they are positioned in reference to the spinning axis. Think slender bodies are easier to rotate compared to wider bodies with same mass. That’s what they mean when earth slightly flattens out its becoming less slender and more difficult to rotate