F= G (m1)(m2) / r^2?

Question

Three 7.31 kg masses are at the corners of an equilateral triangle and located in space far from any other masses. If the sides of the triangle are 1.20 m long, calculate the magnitude of the net force exerted on each of the three masses.

Answer 1

Call the masses Ma, Mb, and Mc. Consider the attraction of Mc to the other 2, one at a time.

Plug into the equation m1=Ma and m2=Mc. This gives you the attraction of Mc toward Ma.

Repeat the above paragraph with m1=Mb and m2=Mc. This gives you the attraction of Mc toward Mb.

So you have 2 vectors pointing 60 degrees apart. Find the resultant.