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: Gravitation/Dynamics problem

  1. Nov 12, 2006 #1
    two 6.3 kg balls with radii of .11m are in contact w/ eachother. what is the gravitational attraction b/w the balls.

    radius = .11m
    mass = 6.3kg

    Fg = G*m1*m2/ [tex] r^2 [/tex]

    i just tried pluggging in the givens and somehow it's a trick question and i get the incorrect answer.
    i shold be getting 5.47E-8.
     
    Last edited: Nov 12, 2006
  2. jcsd
  3. Nov 12, 2006 #2
    testttt,,,
     
    Last edited: Nov 12, 2006
  4. Nov 12, 2006 #3

    Hootenanny

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    What is the distance between the centres of mass of the balls?
     
  5. Nov 12, 2006 #4
    hmm .11m x 2?
     
  6. Nov 13, 2006 #5

    Hootenanny

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Look's good to me. If you do the arithmetic correctly, you should obtain the correct answer.
     
  7. Nov 13, 2006 #6
    yes. thank you. i also had a problem where the Fg is given and you have to find the masses. one mass is twice the other.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook