[填空题]
The tires of a car make 8qlx(e1ijs5 z2 m 2k5 er0)a9xk de2kxlpuxv :)5 revolutions as the car reduces its speed uniformly from 90km/h xu 0d rp5)mkx)vl2 29e:kxake to 60km/h The tires have a diameter 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