• FRYD@sh.itjust.works
    link
    fedilink
    English
    arrow-up
    0
    ·
    10 hours ago

    I just did a quick read on it on it. “Work” is the application of force over time in the direction the object is moving. Pushing a shopping cart for example is work, because you have to constantly apply force to it.

    From what I’ve read, it seems that magnetic force doesn’t do work because it doesn’t apply force in the direction the object moves. Magnetic force only “deflects” or changes the direction of an object with an existing velocity. It’s only a deflection because the force applied is always perpendicular to the direction of the velocity.

    To use the previous shopping cart example, picture a shopping cart that already has a forward velocity that passes a magnet. The magnet only applies a force to the side of the cart towards the magnet. This doesn’t push the cart itself, but changes the direction of its velocity towards the magnet.

    • Log in | Sign up@lemmy.world
      link
      fedilink
      English
      arrow-up
      2
      ·
      8 hours ago

      But that’s true of gravitational forces too, otherwise satellites wouldn’t have constant speed. It’s silly and misleading to say that magnetic forces do no work. If I turn an electromagnet on next to a spoon, the spoon will move and the magnetic force did some work.

      • mexicancartel@lemmy.dbzer0.com
        link
        fedilink
        English
        arrow-up
        1
        ·
        8 hours ago

        Gravity does no work on satellites or objects that go in circular orbits. The force is there but it does no work and hence no energy change/transfer. Work is defined based on energy change by work-energy theorem

        • Log in | Sign up@lemmy.world
          link
          fedilink
          English
          arrow-up
          0
          ·
          5 hours ago

          My point is that whether a force does work doesn’t depend on what the force is. It makes no more sense to say that magnetic forces do no work than it does to say that gravitational forces do no work.