A shaft carries four masses in parallel planes A, B, C and D in this orderalong its length. The masses at B and C are 18 kg and 12.5 kg respectively, and each has aneccentricity of 60 mm. The masses at A and D have an eccentricity of 80 mm. The angle betweenthe masses at B and C is 100° and that between the masses at B and A is 190°, both beingmeasured in the same direction. The axial distance between the planes A and B is 100 mm andthat between B and C is 200 mm. If the shaft is in complete dynamic balance, determine :1. The magnitude of the masses at A and D ; 2. the distance between planes A and D ; and3. the angular position of the mass at D.