[填空题]
A 70-cm-diameter wheelz /r1 9g9cnyzs accelerates uniformly about its center fromx,62t7gtm ixuyz :2zeblmi) mz2+ u9d 130 rpm to 280 rpm in 4.0 s. , e29umlz+72gmm2x:idyi bu6zzxtt)Determine (a) its angular acceleration,$\approx$ $rad/s^2$(Round to one decimal places) (b) the radial and tangential components of the linear acceleration of a point on the edge of the wheel 2.0 s after it has started accelerating. $a_R$ $m/s^2$ $a_{tan}$ $m/s^2$