[填空题]
A 70-cm-diameter wheegzs28 ln2urz) g1 bgc5l accelerates uniformly about 4-k zsahmb nwqnfw985+q t9e4its center from 130 rpm to 280 rpm i9 94b qsqaz+h- t nmw485wkenfn 4.0 s. 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. $a_R$ $m/s^2$ $a_{tan}$ $m/s^2$