# Gravitation/Dynamics problem

1. Nov 12, 2006

### mikejonesss

two 6.3 kg balls with radii of .11m are in contact w/ eachother. what is the gravitational attraction b/w the balls.

mass = 6.3kg

Fg = G*m1*m2/ $$r^2$$

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. Nov 12, 2006

### mikejonesss

testttt,,,

Last edited: Nov 12, 2006
3. Nov 12, 2006

### Hootenanny

Staff Emeritus
What is the distance between the centres of mass of the balls?

4. Nov 12, 2006

### mikejonesss

hmm .11m x 2?

5. Nov 13, 2006

### Hootenanny

Staff Emeritus
Look's good to me. If you do the arithmetic correctly, you should obtain the correct answer.

6. Nov 13, 2006

### mikejonesss

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.