[填空题]
A 70-cm-diameter wheel accej rsm1)a0z/bblerates uni se9.kiu,38 e;ewq npzformly about its center from 130 rpm to 280 rpm s9ek 3u pni,8;qzewe.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. $a_R$ $m/s^2$ $a_{tan}$ $m/s^2$
