[填空题]
The blades in a blender rotate at a rate xv al42 tpgdn x+ak(-0of 6500 rpm. When the motor is turneuy w(3,zhlm *w: .n qk*feyzlh5s,g.dd off during operation, the bdnwl.sz:u 3q,eyzgf *y(5*h,wlhk. mlades slow to rest in 3.0 s. What is the angular acceleration as the blades slow down? $rad/s^2$