Consider the system below, formed by a beam of negligible mass, on which three concentrated masses are positioned as illustrated.The. Determine the stiffness matrix of the system. Consider L1= L2/2 =...

Consider the system below, formed by a beam of negligible mass, on which three concentrated masses are positioned as illustrated.The. Determine the stiffness matrix of the system. Consider L1= L2/2 = L3 = L/4 and write the result as a function of L.B. Assume that the beam is made of aluminum (E=70 GPa), has a square cross section with a 0.015 m side and length L=0.9 m. First consider m1 = 2*m2 = m3 = 20kg. Determine the natural frequencies and modal forms of the system.