In a large centrifuge used for training pilots and astronauts, a small chamber is fixed at the end of a rigid arm that rotates in a horizontal circle. A trainee riding in the chamber of a centrifuge rotating with a constant angular speed of 2.8 rad/s experiences a centripetal acceleration of 3.1 times the acceleration due to gravity. In a second training exercise, the centrifuge speeds up from rest with a constant angular acceleration. When the centrifuge reaches an angular speed of 2.8 rad/s, the trainee experiences a total acceleration equal to 4.3 times the acceleration due to gravity.

(a) How long is the arm of the centrifuge? m

(b) What is the angular acceleration (magnitude) of the centrifuge in the second training exercise? rad/s2