A structure is modeled as damped oscillator with spring constant $k=5\frac{kN}{m}$ and

undamped natural frequency $(1)=25ra\frac{d}{sec}.$ Experimentally it was found that a force $5$ kN

piroduced a relative velocity of $25m\frac{m}{sec}$ in the damping clement. Find $($a$)$ damping ratio..

$($b$)$ logarithmic decrement $($c$)$ damped period $($d$)$ ratio between two consecutive amplitudes

$(4)$