2396

Physics Rotational Mechanics Level: High School

Conservation of Angular Momentum

A student sits on a freely rotating stool holding two weights , each of mass 2.91 kg . When his arms are extended horizontally , the weights are 1.00 m from the axis of rotation and he rotates with an angular speed of 0.759 rad / s . The moment of inertial of the student plus stool is 2.91 kg*m^2 and is assumed to be constant . The student pulls the weights inward horizontally to a position 0.292 m from the rotation axis .

a) Find the new angular speed of the student .

b) Find the kinetic energy of the rotating system before and after he pulls the weights inward .