Absolute value of the acceleration of a rolling disc?

he rod AB is attached to the disc A through a pin joint. The length of the rod is equal to the diameter of the disc. The value of R is given below.

The end of the rod B slides along the ground while point A follows the movement of the disc.

The angular velocity and the angular acceleration of the disc are 3 rad/s and 9 rad/s^2, respectively, in the directions shown in the image

What is the absolute value of the acceleration (m/s^2) of point B?

R[m] = 0.8;

rolling disc picture by jcastlemaine - Photobucket