A ceiling fan consists of a small cylindrical disk with 5 thin rods coming from the center. The disk has mass md = 2. 7 kg and radius r = 0. 25 m. The rod each have mass mr = 1. 2 kg and length l = 0. 82 m. When the fan is turned on, it takes t = 3 seconds and a total of 15 revolutions to accelerate up to its full speed. Now the fan is turned to a lower setting where it ends with half of its rotational energy as before. The time it takes to slow to this new speed is also t = 3s. What is the magnitude of the angular acceleration while the fan is slowing down: rotational dynamics page 1. A disk with mass m = 8. 8 kg and radius r = 0. 36 m begins at rest and accelerates u(cid:374)ifor(cid:373)ly for t = 16. (cid:1008) s, to a fi(cid:374)al a(cid:374)gular speed of = (cid:1007)1 rad/s.