Answer:
damped natural frequency = 23.84 rad/s
Explanation:
given data
damping ratio = 0.3
undamped natural frequency = 25 rad/s
to find out
damped natural frequency of a second order system
solution
we know that if damping ratio is = 0
then it is undamped system
and if damping ratio is > 1
then it is overdamped system
and and if damping ratio is ≈ 1
then it is critical damped system
so damped natural frequency of a second order system formula is
damped natural frequency = wn × 
here wn is undamped natural frequency and r is damping ratio
damped natural frequency = 25 × 
damped natural frequency = 23.84 rad/s