Find the natural frequency of the system shown below for

Question

Question: Find the natural frequency of the system shown below for small rotations of the rocker arm. Neglect the mass of the spnng. The cam turns on a fixed shaft and drives the push rod up and down. The action of the push rod rotates the rocker arm about O which drives the valve down and up.

Push rod mass = 0.5 kg                   Rocker arm mass = 0.9 kg

Valve mass = 0.75 kg                      Rocker arm mass moment of inertia about CG at G = 12.0*10^-3 kg*m²
                                                  Spring constant = 2500 N/m