1. The problem statement, all variables and given/known data I am trying to calculate the natural frequency of a steel beam. 2. Relevant equations I=1/12*W*T^3 Volume= T*W*L M0=V*ρ K=(3EI/L^3) Meff=(33/140)*M0+Mend ωn=√(k/Meff) 3. The attempt at a solution This should be a simple plug and chug problem but I can't see what I'm doing wrong. L=0.4572m W=0.026035m T=0.006223m E= 3*10^6 ρ=7850kg/m^3 Mend=.025kg I=5.22848E-10 V=7.41E-05 m^3 M0=5.81E-01 K=0.049237907 Meff=2.43E-01 ωn=0.450088787 Hz But this is way off from my experimental value of around 20Hz. Everything is in kg and m.