Aprinted circuit board (pcb) is supported by a chassis that is attached to a vibrating motor. the board is 1.6 mm thick, 200 mm wide, 254 mm long, and has a mass of 0.6 kg. neglect damping, model the board as a doubly clamped beam, determine its stiffness and natural frequency, and compute the displacement transmissibility if the chassis vibrates at 60 hz due to motor unbalance. the board is made from e poxy fiberglass for which e = 1.38 x 10^10 n/m2