The distance of a particle moving on a circle of radius 12 m measured from a fixed point on the circle and measured along the circle is given by s=2t3 (in meters). The ratio of its tangential to centripetal acceleration at t=2s is :
(1) 1 : 1
(2) 1 : 2
(3) 2 : 1
(4) 3 : 1