[填空题]
A uniform disk turns a),0cz2r0dc 4w-w,xrtdnr zla s uei20t 26yhj9 .j lv ca.-ji -h:dh:xkr der1/b.4 $rev/s$ 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? $rev/s$