An aluminum rod of length L = 1m has mass density p = 2700K and Young's modulus E = 70 GPa. The rod is fixed at both ends. The exact natural eigenfrequencies of the rod are exact - = L for n=1,2,3,.... 1. What is the minimum number of linear elements necessary to determine the fundamental frequency w of the system? Discretize the rod in that many elements of equal length, assemble the global system of equations KU = w MU, and find the fundamental frequency w1. Compute the relative error e = = (w1 - wexact) /w exact Sketch the fundamental mode of vibration.