Solve the below problem:
Q: A 27-kg disk is attached with an eccentricity e = 150μm to the midpoint of a vertical shaft AB which revolves at a constant angular velocity ωf. Knowing that the spring constant k for horizontal movement of the disk is 580kN/m, determine
(a) The angular velocity ωf at which resonance will occur,
(b) The deflection r of the shaft when ωf = 1200 rpm.
![2428_Shaft.jpg](https://secure.tutorsglobe.com/CMSImages/2428_Shaft.jpg)