6. A horizontal tabletop is divided into two parts that have different surface texture. A thin uniform disk spinning clockwise about its axis is placed on tabletop. The coefficients of sliding friction between them are i1=3/8,i2=1/4 as shown . initially the center of disk is located right over the line dividing the tabletop. The initial acceleration of the C.O.D. is given by g/xpi then x is.