[填空题]
The tires of a car make 85 revolutions as the car reduces q) fu(rss5p(n- 3w+y4scyfvu ix :evv+z:uf )ats speed uniformly from 90km/h to 60evvz +:a:fu )xkm/h The tires have a 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