Three bodies each of mass 'm' are placed at the three corners of a square of side 'a'. The gravitational force on unit mass kept at the fourth corner is

Three bodies each of mass 'm' are placed at the three corners of a squ

1.	Three bodies each of mass 'm' are placed at the three corners of a square of side 'a'. The gravitational force on unit mass kept at the fourth corner is
Answer» `(GM)/(3a^2)` `(Gm)/(SQRT(3)a^2)` `(3Gm)/(a^2)` `(Gm)/(a^2) (sqrt(2)+(1)/(2))` ANSWER :D