A catapult with a radial arm 4.15 m long accelerates a ball of mass 18.7 kg through a quarter circle. The ball leaves the apparatus at 49.7 m/s. The mass of the arm is 27.7 kg and the acceleration is constant. Hint: Use the time-independent rotational kinematics equation to find the angular acceleration, rather than the angular velocity equation.
(a) Find the angular acceleration.
rad/s2
(b) Find the moment of inertia of the arm and ball.
kg · m2
(c) Find the net torque exerted on the ball and arm.
N · m