physics
posted by Kelsey .
Objects with masses of 190 kg and a 490 kg are separated by 0.380 m.
(a) Find the net gravitational force exerted by these objects on a 57.0 kg object placed midway between them.
N
(b) At what position (other than infinitely remote ones) can the 57.0 kg object be placed so as to experience a net force of zero?
____ m from the 490 kg mass
I figured out the first part is 3.1E5N
by using the G(m1*m2)/r^2 formula.
but I have no idea how to do it not knowing either distance.
I tried to set the equations equal to eachother and use different variables for both of the distances but the I don't think I can end up with a variable in the answer....

b. let x be one distance, and .380x the other distance. Set the forces at these distances equal.
G190/x^2=G490/(.380x)^2
solve for x.