Posted by colleen on .
Two uniform spheres , each of mass M and radius R, touch one another. What is the magnitude of their gravitational force of attraction?

physics 
bobpursley,
Isn't the distance the centers of mass are apart 2R?

physics 
Marth,
Fg = G*m1*m2/r^2
And as bobpursley noted, the r (distance) is 2 * R.
Try to solve for Fg.