[填空题]
A 70-cm-diameter wheel accelerates unifoa6rd)9 jygh1zhl :1c nrmly about its center+vej :sn;klh3y g tg:6 from 130 rpm to 280 rpm in 4.0 s. yt+ ej;3l:g6vh:kn sg 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. $a_R$ $m/s^2$ $a_{tan}$ $m/s^2$