[填空题]
The tires of a car make gt,cl0 o5y /dl85 revond6v *f/m nz qte-(g9xlutions as the car reduces its speed uniformly from 90km/h to 60km/h The tires have a diameter of 0.90 m -vmtnxn d* e96/q(gfz. (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