[填空题]
A hammer thrower acco06ak/ sesz2selerates the hammer from rest within four full turns (re ;dn-5 mvkr y;, 2yj /;i)1hrznscurkevolutions) and releases it at a syz;; r ekkh5nr 1 u/i);rvs2- j,dyncmpeed of 28 $m/s$ Assuming a uniform rate of increase in angular velocity and a horizontal circular path of radius 1.20 m, calculate (a) the angular acceleration, $rad/s^2$ (b) the (linear) tangential acceleration, $m/s^2$ (c) the centripetal acceleration just before release, $m/s^2$ (d) the net force being exerted on the hammer by the athlete just before release, N (e) the angle of this force with respect to the radius of the circular motion. $^{\circ} $