The forces involved when vibration happens are
1) The exciting force such as unbalance or misalignment
2) The mass of the vibrating system.
3) The stiffness of the vibrating system
4) The damping characteristics of the vibrating system.
1
1 and 3
2
1,3 and 4
3
1,2 and 3
4
1,2,3 and 4