[填空题]
The tires of a car make 85 revr (jp) mv:c2jy(f gd myp:(.lyolutionp-c maf/hq ) q kc700p;1sjpwps as the car reduces its speed uniformly from 90km/h to 60km/h The tires have a diameter of 0.90 m. (a) What wama0/hp1pcp7w ;s pk) c0qf q-js 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