A ceiling fan consists of a small cylindrical disk with 5 thin rods coming from the center. The disk has mass md = 2.9 kg and radius R = 0.26 m. The rods each have mass mr = 1.4 kg and length L = 0.8 m. When the fan is turned on, it takes t = 3 s and a total of 15 revolutions to accelerate up to its full speed. What is the magnitude of the angular acceleration? ______ Angular acceleration=dw/dt. So if it makes 15 revolution, and each revolution is 2pi, then we have 15*2pi which is 94.24. If we divide that by the time, we get 31.41, which is I think angular velocity. The question is what is the change in angular velocity? Then I can use that to find angular acceleration..