[填空题]
A hammer thrower accele)s t6v98)inqts b1sa kd2-zn(dkz9 korates the hammer from rest withi0 y7c2sksfyz l2ole+k08 oa; sn four full turns (revolutions) and releases it at a speey c fk2oya+ 28s0 o7;leskzls0d 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} $