[填空题]
The blades in a blender6 /.rkpz.p 4kr+zvmqm rotate e3hb(q8:kpr5 qf0ip vat a rate of 6500 rpm. When the motor is turned off during operation, the blades slow to repe:q 50kvph83bqif r (st in 3.0 s. What is the angular acceleration as the blades slow down? $rad/s^2$