[填空题]
The tires of a car make 85 revolutions as the car r:pf c3r.2 zvf kka068ayuni( eeduces it 5xf(7o eiw m)92tnaers speed uniformly from 90km/h to 60km/h The tires have a diameter of 0.90 m. (a) What was the angular m)teeorn 7( f9wiax52acceleration 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