Question

You have a pulley 13.9 cm in diameter and with a mass of 1.7 kg. You get to wondering whether the pulley is uniform. That is, is the mass evenly distributed, or is it concentrated toward the center or the rim? To find out, you hang the pulley on a hook, wrap a string around it several times, and suspend your 1.1 kg physics book 1.3 m above the floor. With your stopwatch, you can find that it takes 0.66 s for your book to hit the floor.