[填空题]
A uniform disk turns(:i9fx x.m1p mu4w1tq q:aau h at 2.vqacjom u38v.b ,t2y3 aunq8 84 $rev/s$ around a frictionless spindle. A nonrotating rod, of the same mass as the disk and length equal to the disk’s diameter, is dropped onto the freely spinning disk, Fig. 8–49. They then both turn around the spindle with their centers superposed. What is the angular frequency in rev/s of the combination? $rev/s$