The magnitude of the acceleration of the point of contact on the disc is

Question

1. A solid disc of radius r rolls without slipping on a horizontal floor with angular velocity $\omega$ and angular acceleration $\omega \alpha$. The magnitude of the acceleration of the point of contact on the disc is                                   

      (a) zero                                                               (b) rα

      (c) ) rω²                                                             (d)$\sqrt{(r\alpha )2+(r\omega )}$