1. The problem statement, all variables and given/known data At a certain instant, the earth, the moon, and a stationary 1030kg spacecraft lie at the vertices of an equilateral triangle whose sides are 3.84×10^5km in length. Find the magnitude of the net gravitational force exerted on the spacecraft by the earth and moon. 2. Relevant equations GMm/r^2 = Fg r = 3.84*10^5 km Me = 5.98*10^24 kg Mm = 7.35*10^22 kg G = 6.67*10^-11 Ms = 1030kg 3. The attempt at a solution http://imgur.com/p8OBdfd I think it's probably a simple error somewhere but I've gotten about 3-4 different answers all which are not F=2.8N - I've tried calculating it at different stages in the algebra - are the angles somehow not based off 60*? I don't know what it's missing.