मुक्त कंपन (free vibration) में, वेग वेक्टर, विस्थापन वेक्टर से कितने कला कोण (phase angle) से आगे होता है?

A system is said to be critically damped if the damping factor (ζ) for a vibrating system is ___________.

In an undamped free longitudinal vibration of a spring-mass system, the total mechanical energy:

A vibrating system is said to be critically damped if its damping ratio (ζ) is equal to: