1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Self-supply gravity motor

  1. Nov 13, 2013 #1
    Is it possible to create enough energy( by letting a pound falling to crank a rotor) to bring back up the pound?
  2. jcsd
  3. Nov 13, 2013 #2


    Staff: Mentor

    There is always some energy lost due to friction so that you get less stored energy than would be needed to bring the weight back to its original position.
  4. Nov 13, 2013 #3
    if you use a trampolin at the end to help a little the lift?
  5. Nov 13, 2013 #4
    Nope. There is no way around energy conservation and there will always be some losses.

    You should read up on perpetual motion machine of the third kind.
  6. Nov 13, 2013 #5


    User Avatar
    Gold Member

    It's possible IF,no external forces were present.but this is not the case of our universe(as far as I know of it)Friction and air-resistance will of course make it lose energy.
  7. Nov 13, 2013 #6
    It's not even an issue of external forces like friction or air resistance, even the simple act of accelerating the mass causes it to emit gravity waves and lose energy.
  8. Nov 13, 2013 #7
    if you help the pound with magnetic force?
  9. Nov 13, 2013 #8


    User Avatar

    Staff: Mentor

    I'm sorry, we don't discuss ideas for perpetual motion machines here, even to debunk them.

    You can find some useful links in our list of banned topics, under 'Perpetual motion and "free energy" discussions', in the second post of our 'Rules & Guidelines' thread:

Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook