A spring has a force constant of 371 N/m and an unstretched lengthof 6 cm. One end is attached to a post that is free to rotate inthe center of a smooth table, as shown in the top view below. Theother end is attached to a 4 kg disk moving in uniform circularmotion on the table, which stretches the spring by 3 cm.
Note: Friction is negligible.
What is the centripetal force Fc on the disk?