The figure shows the inside of an instrument that is used to measure the amplitude Y of the vertical ground motion y(t) = Y sin ωt. The L-shaped arm is in equilibrium in the position shown. Derive the equation of motion for the mass m in terms of z, the displacement of the mass relative to the frame. Assume small displacements and neglect all masses except m.
![1975_f70da4a6-b233-44bc-92bd-af0334a048aa.png](https://secure.tutorsglobe.com/CMSImages/1975_f70da4a6-b233-44bc-92bd-af0334a048aa.png)