The damped natural frequency \( \omega_d \) is related to the undamped natural frequency \( \omega_n \) and the damping factor \( \zeta \) by the following formula:
\( \omega_d = \omega_n \sqrt{1 - \zeta^2} \)
Given that \( \omega_n = 80 \, \text{rad/sec} \) and \( \zeta = 0.7 \), we can calculate the damped natural frequency as:
\( \omega_d = 80 \sqrt{1 - (0.7)^2} = 80 \times 0.714 \approx 67.13 \, \text{rad/sec} \)
| LIST I | LIST II |
| A. Reynold’s Number | III. Inertia force to viscous force |
| B. Mach Number | I. Inertia force to elastic force |
| C. Froude’s Number | II. Inertia force to gravity force |
| D. Weber’s Number | IV. Inertia force to surface tension force |