A light spring has unstressed length 15.5cm.It is described by Hooke's law with spring constant 4.30N/m.One end of the horizontal spring is held on a fixed vertical axle,and the other end is attached to a punk of mass that can move without friction over a horizontal surface.The punk is set into motion in a circle with a period of 1.30s.
Find the extension of the spring x as it depends on m.
The Attempt at a Solution
Firstly,I found the velocity of the punk.
But I don't know what is the next step.