[填空题]
The tires of a car make 81x08o 5apmsr p3d v:us5 revolutionsri1odv0 ij5g) as the car reduces its speed uniformly from 90km/h to 60km/h The tires have a d iv01)5io djrgiameter 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