A Cantilever beam of SiO2 of length 100μm, width 20μm and thickness of 5μm. How to calculate the resonant frequency? I know f=1/2∏√(k/m) where k=3EI/L^3 and mass = l*w*h *ρ (density) and I = w*t^3/12, but i don't get the desired answer. pl correct me. What changes are to be considered for the natural frequency if the cantilever is coated by a gold layer of 0.5μm uniform thickness forming a composite beam. thanks in advance.