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!

Momentum or Earth?

  1. Jun 24, 2012 #1
    Momentum of Earth?

    Earlier I was thinking about circular motions and centripetal forces and the earth around the sun, If p=mv and the velocity of a object in circular motion is constantly changing does this mean Earth's momentum is constantly changing?
    or is it that earth is travelling on a straight path through curved space-time and does not have centripetal force?
    Last edited: Jun 24, 2012
  2. jcsd
  3. Jun 24, 2012 #2


    User Avatar
    Science Advisor

    Re: Momentum of Earth?

    That is Einsteins model of gravity. In a local inertial frame frame the momentum of the Earth doesn't change. But you cannot extend the inertial rest frame of the Sun to include Earth. Inertial frames are only local in curved space-time.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook