A 60-lb disk is attached with an eccentricity e 0006 in to

Question

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 ω_f at which resonance will occur,

(b) the deflection r of the shaft when ω_f = 1200 rpm.