A uniform rod AB of mass \( 2 \, \text{kg} \) and length \( 30 \, \text{cm} \) at rest on a smooth horizontal surface. An impulse of force \( 0.2 \, \text{Ns} \) is applied to end B. The time taken by the rod to turn through at right angles will be \( \dfrac{\pi}{x} \, \text{s} \), where \( x = \) __________.
