30 . A wooden beam is pivoted about one end . A ball traveling at a velocity of 4 m/'s hits and sticks to the beam at the other end , causing the

30 . A wooden beam is pivoted about one end . A ball traveling at a velocity of 4 m/'s hits and sticks to the beam at theother end , causing the beam to have a maximum angular displacement of a . Which of following statements are true ?_Hooka .The final angular momentum of the ball - beam system is equal to the initial angular momentum of the ball ;b .The total energy of the ball - beam system when at a is equal to the initial kinetic energy of the ball ;C.The total energy of the ball - beam system when at a is equal to the initial kinetic energy of the ball - beam systemimmediately after collision ;d .Both kinetic energy and angular momentum are conserved through the collision .E.The net torque done on the ball - beam system is proportional to the moment of inertia of the rod .