When a 5kg mass is hung from a vertical spring,it streches by 25cm.(a)what mass must be supported by d spring in order to make d system vibrate wit a period of 1s.(b)if d amplitude of d motion is 5cm,determine d position nd d velocity of d mass 0.3s afta passing d equilibrium position on its way downward.(c)what is the restoring force on d mass@dis instant?