[填空题]
The blades in a blender j06;ts2 b od6u fu:anwrotate at a rate of 6500 rpm. When the )zc91nwdyftr d; 0ngd(m )kw- motor is turned off during operation, the blades slow1dy cd w) nr90wm();ktznfg-d to rest in 3.0 s. What is the angular acceleration as the blades slow down? $rad/s^2$