The steel frame shown in the figure supports a rotating machine that exerts a horizontal force at the girder level P(t) = 890 sin 5.3t (N). Assuming 5% of critical damping. Determine: (a) the steady...

Extracted text: The steel frame shown in the figure supports a rotating machine that exerts a horizontal force at the girder level P(t) = 890 sin 5.3t (N). Assuming 5% of critical damping. Determine: (a) the steady state amplitude of vibration and (b) the maximum dynamic stress in the columns (the girder is rigid). 5 m = 7 ton h 4.5 m I = 288 * 10 mmt (each column) E= 2*10 MPa Pit)