Problem 5: At its lowest setting a centrifuge rotates with an angular speed of w1 = 250 rad/s. When it is switched to the next higher setting it takes t = 7.5 s to uniformly accelerate to its final angular speed w2 = 750 rad/s. Part (a) Calculate the angular acceleration of the centrifuge al in rad/s2 over the time interval t. Part (b) Calculate the total angular displacement (in radians) of the centrifuge, 40, as it accelerates from the initial to the final speed. Problem 6: Case 1: A DJ starts up her phonograph player. The turntable accelerates uniformly from rest, and takes t1 = 10.2 seconds to get up to its full speed of f1 = 78 revolutions per minute. Case 2: The DJ then changes the speed of the turntable from f1 = 78 to f2 = 120 revolutions per minute. She notices that the turntable rotates exactly n2= 12 times while accelerating uniformly. Part (a) Calculate the angular speed described in Case 1, given as f1 = 78 revolutions per minute, into units of radians/second, Part (b) How many revolutions does the turntable make while accelerating in Case 1? Part (c) Calculate the magnitude of the angular acceleration of the turntable in Case 1, in radians/second2. Part (d) Calculate the magnitude of the angular acceleration of the turntable (in radians/second2) while increasing to 120 RPM (Case 2). Part (e) How long (in seconds) does it take for the turntable to go from f1 = 78 to f2 = 120 RPM? Problem 7: The angular speed of a rotating platform changes from wo =4.2 rad/s to w = 6.2 rad/s at a constant rate as the platform moves through an angle 40 = 5.5 radians. The platform has a radius of R = 12 cm Part (a) Calculate the angular acceleration of the platform a in rad/s2. Part (b) Calculate the tangential acceleration at in m/s2 of a point on the surface of the platform at the outer edge. Part (c) Calculate the final centripetal acceleration ac, in m/$2, of a point at the outer edge of the platform