Estimate the two different natural frequencies measured in the lab (in steps 3 and 5). Use the two different natural frequencies and the two different known masses to obtain the approximate stiffness of the beam. In your calculations, you should consider the mass of the beam; you can estimate that value if you know the cantilevered length of the beam, its cross-sectional area, and the density of aluminum.
Compare the measured stiffness of the beam to the theoretical stiffness listed in the equation on the previous page.
How do the two compare?