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!

Net grav force

  1. Oct 13, 2007 #1
    1. The problem statement, all variables and given/known data
    Each ball weighs 3.00 kg A is 10cm from C to the left and B is 40cm to the right of A

    2. Relevant equations


    3. The attempt at a solution

    ive tried adding the forces that each ball apply to A and subtracting it. i know each has its own force acting on A but dont know how to figure it out with 3 objects
  2. jcsd
  3. Oct 14, 2007 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Force is a vector. You have two force acting in opposite directions on ball A. How would you work out the net force then?
  4. Oct 14, 2007 #3
    Well you already know that each force is acting in the x direction and with gravity the farther away the less the gravitational force so wouldnt you just have to subtract the sum of each force?
  5. Oct 14, 2007 #4
    F=6.67e-11 (3kg) (3kg))/.04^2 i calculated that for the force of B on A and i got 3.75e-7N

    for force of C on A i got 6.003e-7N. Now each of these balls is exerting its own force on A but one is stronger than the other because of the distance so isnt the net force just calculated by the difference?
  6. Oct 14, 2007 #5


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    If you have to calculate the net force on A then both balls B and C are to the right of it and the forces will add. I was a bit unsure which ball you were wanting to calculate the net force on. The description of the system was a bit ambiguous as well.
  7. Oct 14, 2007 #6
    In the picture given to me Ball C is to the left of A and ball B is to the right they are on different sides sorry if the description was hazy.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Net grav force
  1. Net Force? (Replies: 17)

  2. Net Force and Net Work (Replies: 1)

  3. Net Force (Replies: 3)