[填空题]
The blades in a blender rotatem,7.. + o4ig 797ekze;pq,tyfnzix mejxe( hk at a rate of 6500 rpm. When tea qo35k aezttis++h.jy;v/ d/2/blhhe motor is turned off during operation,/dz l+ qh;.a5/a2hjt/eoysve+ k3 bit the blades slow to rest in 3.0 s. What is the angular acceleration as the blades slow down? $rad/s^2$