[填空题]
A 70-cm-diameter wheel csju0dt( lbo ei/y 7-l(85ygmaccelerates unifo 5q1q7rpw sfdpy4u5 ,gk+p.(fads*e frmly about its center from 130 rpm to 280 rpm in. wqr*ppuq7 5kgs1a5f,fyf (p d4ed s+ 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. $a_R$ $m/s^2$ $a_{tan}$ $m/s^2$