A flat platform rotates in a horizontal plane about a fixed vertical axis that passes through O. A small disk of 0.5 kg is connected to the centre O with a 5 m long string. The friction coefficients between the disk and the platform are Mu static = 0.90 and Mu kinetic = 0.80. If suddenly the string breaks,
a.) what happens to the disk if the platform is undergoing uniform circular motion, so that the speed at A is constant and equal to 2 m/s
b) Find the horizontal force exerted on the disk if the angular velocity and angular acceleration of the platform are 1.2 rad/s and 0.6 rad/s^2 at the instant when the string breaks