[填空题]
A 70-cm-diameter wheel accelerates unifp-rmbkc; l(0w ormly about its1)w0-6oi.pw :. l t(u6cbgpdafbnckq center from 130 rpm to 280:6.0pwt k cg6)o.wfqiac-pun1(lbdb rpm in 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. $a_R$ $m/s^2$ $a_{tan}$ $m/s^2$