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!

Homework Help: Calculate the change in gravitational potential energy

  1. Oct 28, 2012 #1
    1. The problem statement, all variables and given/known data
    A satellite of mass 750kg is changed from an orbital radius of 7000000m to a geostationary orbit of 4.2*10^4. Calculate the change in its gravitational potential energy

    Mass= 750
    Earths radius= 6380000m
    Gravitational constant= 6.67*10^-11
    Earths mass=6*10^24

    2. Relevant equations

    So I am guessing I have to use this equation
    Final Gpe- initial Gpe

    3. The attempt at a solution
    = 1.69 *10^10

    The answer is 3.7*10^8
    I don't know where I went wrong?
  2. jcsd
  3. Oct 28, 2012 #2
    what is the new radius?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook