Answer
given,
mass of object
m₁ = 130 Kg
m₂ = 430 Kg
distance between them = 0.3 m
a) net force when 35 kg is place in between them
![F = (GMm)/(R^2)](https://img.qammunity.org/2020/formulas/physics/college/vxaq0k8vt9c1wpxwwwvewaz3cznee6kunt.png)
now,
![F = - (6.67 * 10^(-11)* 130 * 30)/(0.15^2) +(6.67 * 10^(-11)* 430 * 30)/(0.15^2)](https://img.qammunity.org/2020/formulas/physics/college/hd6kxabuzn1ooeosatp77k1qdsuul54gh4.png)
![F = 3.12 * 10^(-5)\ N](https://img.qammunity.org/2020/formulas/physics/college/ihsq1g1cph599jhhmxw61zadq8tj0849oc.png)
Direction of force will be toward the mass of 430 Kg
b) position where force will be zero
![F =-(6.67 * 10^(-11)* 130 * 30)/((0.3-x)^2) +(6.67 * 10^(-11)* 430 * 30)/(x^2) = 0](https://img.qammunity.org/2020/formulas/physics/college/zqf28b3r5bzkogsk4y3haxmjmef3b43nrm.png)
![-(130)/((0.3-x)^2) +(430)/(x^2) = 0](https://img.qammunity.org/2020/formulas/physics/college/up2boz4voy5tfhmxm7wpo2t0bqbz788ekq.png)
![x^2- 0.6 x + 0.09=(130)/(430)x^2](https://img.qammunity.org/2020/formulas/physics/college/nlrksadhfmtjer37ghmsqyuhh0lafxhj1y.png)
![0.7 x^2- 0.6 x + 0.09 =0](https://img.qammunity.org/2020/formulas/physics/college/3ribhhazbu8wkowjtr4jdag0yjfsgmnp2r.png)
solving the above equation
x = 0.1936 m
the distance of third mass will be at x = 0.1936 m from 430 Kg mass.