1.A 3 m high, 8 m wide single-bay single-storey frame is rigidly jointed with a beam of mass 5,000 kg and columns of negligible mass and stiffness of EIc = 4.5×103 kNm2. Calculate the natural frequency in lateral vibration and its period. Find the force required to deflect the frame 25 mm laterally. Ans: 4.502 Hz; 0.222 sec; 100kn. ƒ=(1/2π)*(√(k/m) How can I get the k from given values.