[SOLVED] newton theory of gravity 1. The problem statement, all variables and given/known data what are the magnitude and direction of the net gravitational force on the 20kg mass. Now this is kinda tricky but there is an 20kg ball on the origin, and two 10kg balls 20cm above the x axis, and one is 5cm right and the other is 5cm left of the y axis. 2. Relevant equations F=GMm/R^2 G=6.67x10^-11 3. The attempt at a solution F(on m1)=F(m2 on m1)+F(m3 on m1) F(m2 on m1)=GMm/R^2=(6.67x10^-11*20*10)/0.2^2=3x10^-7jN F(m3 on m1)=" "=" "=" ' " Thus F(on m1)=3x10^-7j+3x10^-7j=6.67x10^-7jN Now i thought this question was kinda straight forward, but in the answers in the book the answer is 3x10^-7jN, half of what i got.... and i dont know where i went wrong, can someone plz help me?