A spring has a force constant of 478 N/m and an unstretched length of 9 cm. one end is attached to a post that is free to rotate in the center of a smooth table. the other end is attached to a 4kg disc moving in uniform circular motion on the table, which stretches the spring by 3 cm. Note: Friction is negligible.

1.What is the centripetal force Fc on the disk? Answer in units of N.

2.What is the work done on the disk by the spring during one full circle?

2 answers

Is the 4kg disk sliding or rolling around the table?

If sliding,

cenripetal force=spring force= Kx=478N*.03

b) work is zero. Force is not in the direction of motion.
It's sliding.... Thank You very much!!!