[填空题]
A 70-cm-diameter wheel accelerates unif 5,zfyq+ badvovs ;4g1ormlyh+deq80h9oa4o 9/ 8k nqhb*dab tn dn5nwb 28h about its center from 130 rpm to 280 nqa/+n h2 *9 hn9aebd58dbh0o8qhb8wnd kt o4rpm 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. $a_R$ $m/s^2$ $a_{tan}$ $m/s^2$
