A 60-lb disk is attached with an eccentricity e = 0.006 in. 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 40,000 lb/ft, determine
(a) the angular velocity ωf at which resonance will occur,
(b) the deflection r of the shaft when ωf = 1200 rpm.
![1283_48134795-d0e9-44f4-9c96-a50852986637.png](https://secure.tutorsglobe.com/CMSImages/1283_48134795-d0e9-44f4-9c96-a50852986637.png)