The rotation of the 0.9-m arm OA about A is defined by the relation theta = 0.15t^2, where theta is expressed in radians and t in seconds. Collar B slides along the arm in such a way that its distance from O is r = 0.9 - 0.12t^2, where r is expressed in meters and t in seconds. After the arm OA has rotated through 30 degrees, determine(a) the total velocity of the collar, (b) the total acceleratin of the collar, (c) the relative acceleration of the collar with respect to the arm.