Two spherical balls are placed so their centers are 6.2 m apart. The gravitational force between the two balls is 2.75x10 ^-12 N. What is the mass of each ball if one ball is twice the mass of the other ball?
I don't know how to start solving this- do i use Fg=Gm1m2/r^2 ?

Question

Two spherical balls are placed so their centers are 6.2 m apart. The gravitational force between the two balls is 2.75x10 ^-12 N. What is the mass of each ball if one ball is twice the mass of the other ball? 
I don't know how to start solving this- do i use Fg=Gm1m2/r^2 ?

farcher · Answer

Use the formula and call the masses m and 2m which will give you an equation for m^2 and hence m.
The distance to use is the centre of one sphere to the centre of the other sphere.