[填空题]
The tires of a car make 85 revolutions as the car reducetotkuh 8a e5tdibu9x+qh8v 4. n ly8.*s it/p(bj6wtefgi 1)8rrq s speed uniformly from 90km/h to 60km/h The tires have a/t1r)bjr(fep wqi 8g6 diameter of 0.90 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