[填空题]
A hammer thrower accelerates the hammer from rest within four full7j35di ) 3a*d1d5xl:bvgimvk1 cl hpl t1 j:fcn*xs:m) ogw ey,ax0qi0urns (revolutions) and releases it at a sj1o:0swc, inxx0: g)qy*efmapeed 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} $