Static and Dynamic balancing of masses

Question

A shaft carries four rotating masses A,B,C and D in sequence along its axis. The masses A, B, C and D are assumed to be concentrated at radii of 12 cm, 16 cm, 8 cm and 10 cm, respectively. The masses of B, C and D are 30 kg, 50 kg and 40 kg, respectively. The planes containing B and C are 30 cm apart. The angular spacing of the planes containing C and D are 90⁰ and 210⁰, respectively relative to B measured in the same sense.

If the system is to be in complete dynamic balance, find -

1. the mass and angular position of mass A;
2. the spacing positions of the planes containing A and B.

Answer 1

From the given data

 

 

 

 

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