In a system with light damping (c < cc), the period of vibration is commonly defined as the time interval d = 2/d corresponding to

In a system with light damping (c < cc), the period of vibration is commonly defined as the time interval τd = 2π/ωd corresponding to two successive points where the displacement-time curve touches one of the limiting curves shown in Fig. 19.11. Show that the interval of time

(a) Between a maximum positive displacement and the following negative displacement is ½τd.

(b) Between two successive zero displacements is ½τd.

(c) Between a maximum positive displacement and the following zero displacement is greater than ¼τd.