The four masses m1, m2, m3 and m4 having their radii of rotation as 200mm, 250mm, 150mm, 250mm and 300mm are 200kg, 300kg,240kg and 260kg in magnitude respectively. The angles between the successive masses are 45 degree, 75 degree and 135 degree respectively. Calculate the magnitude and position of the balance mass needed, if its radius of rotation is 200mm.