an air-conditioning unit weighing 1200 lb is bolted at the middle of two parallel simply supported steel beams. The clear span of the beams is 8 ft. The second moment cross-sectional area of each beam is 10 ^4 in. The motor in the unit runs at 300 rpm and produces an unbalanced force of 60 lb at this speed. Neglect weight of the beams and assume 1% viscous deflection in the system; for steel E=30,000 ksi. Determine the amplitude of steady-state deflection and steady-state acceleration )in (g's) of the beams at the midpoints which result from the unbalanced force