[填空题]
A hammer thrower accelerates the a 6 )5x-qmytwkhammer from rest within four full cr,7isa; a 4jg.:*ruy o.8y e/jf5r)zgb meg pturns (revolutions) and releases it at a sp rm *i5u 7c;j,ebgj8zrpy/ga)yo.4.:rfsa e geed 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} $