[填空题]
The tires of a car make 85 revolutions as the car reduces itjuvgqob 0y-5:- t;d uns speed r/ aay37sb), vqmq, cbuniformly from 90km/h to 60km/h The tires have a diameter of 0.90yvsc r/,,bq) a3m baq7 m. (a) What was the angular acceleration of each tire? $\approx$ $rad/s^2$(round to two decimal place) (b) If the car continues to decelerate at this rate, how much more time is required for it to stop? s