Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Motor which operate solely on magnet and gravity?

  1. Feb 18, 2009 #1
    I received an assignment from my professor which sounds like follow:

    "Suggest a motor which operates only on magnets and gravitational force."

    While I did make a search online and found some model which seems to work, I am sill a little skeptical (There are videos online, but none of them are authentic). Are there any design which full fills such requirement, and has been verified? I was told that such machine would not violate the 2nd Law of Thermodynamics because the magnet itself is the energy source. Can anyone verified / debunk this?

    Thanks in advanced.
     
  2. jcsd
  3. Feb 18, 2009 #2

    mgb_phys

    User Avatar
    Science Advisor
    Homework Helper

    Without any external energy input - it's going to be tricky.
    Otherwise it's quite easy.
    1, Attach plastic paddle wheel to electric motor.
    2, Stand above it
    3, Drop magnets onto paddle wheel.
    4, Motor turns - generates electricity
     
  4. Feb 18, 2009 #3

    Bobbywhy

    User Avatar
    Gold Member

    You may try putting a permanent magnet on a Focault pendulum.
    As the pendulum precesses the magnetic interacts with the earth's magnetic field and adds kinetic energy!
     
  5. Feb 18, 2009 #4

    Ivan Seeking

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    It not only violates the second law, it also violates Ivan's law. :biggrin:

    Perpetual motion/free energy discussions are banned because it [such a motor] would violate the second law.

    There is a small amount of energy stored in the field of a magnet, but only a very little bit. And there is no way to switch it on and off as we would do for a motor using electromagnets, brushes, and a rotor.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Motor which operate solely on magnet and gravity?
  1. Magnetic Motor (Replies: 7)

  2. Shoe Soles (Replies: 25)

  3. Perendev Magnetic Motors (Replies: 20)

Loading...