One end of a massless spring of spring constant 100 N/m is fixed at the centre of a frictionless horizontal table and the other end is connected to a body of mass 7 kg lying on the table at rest. The spring has a natural length of 2 m. If the spring remains horizontal and mass is made to rotate at an angular speed of 1 rad/s, then find the elongation in the spring, assuming the elongation to be small compared to the natural length of the spring.