Four masses m1, m2, m3 and m4 are 160 kg, 225 kg, 200 kg and 312 kg, respectively. The corresponding radii of rotation are 0.25 m, 0.2 m, 03 m and 0.25 m, respectively. The angles between the successive masses are 450, 750 and 1350. Find the position and magnitude of the balance mass required. If its radius of rotation is -.25 m. Presume that all masses including the balance mass rotate in the same plane.