Balancing The need to balance a rotating shaft which is carrying some type of machine element, as shown in figure arises due to a very simple phenomenon called centripetal force. It states that when a mass rotates in circular motion, it requires a force to act on it, always pointing to the center of rotation. This force is required to change the direction of velocity of the object. The mass rotating in fig a will be provided the centripetal force via the link, which in turn is attached to the rotating shaft. According to Newton's third law, the mass will exert an equal and opposite force (reaction force) on the link, and hence on the shaft. This force will cause the shaft to be displaced from equilibrium and hence will induce continuously varying reactions on the bearing. It will also cause a bending moment to form in the shaft. It is for this reason that balancing of rotating shafts is required. The shafts are balanced by adding additional masses on it, in such plane...