[填空题]
The tires of a car make 85 ;,u0um 7 xbhj924qgvrvdkn 2hrevolut7o 8s jrcj;v3yions as the car reduces its speed uniformly from 90km/h to 60km/h The tires have a vscoj ; 3r8y7jdiameter 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