[填空题]
The tires of a car make 85 revolutions a/ nqkxlg:4/zfx n8k 2z i/p+ rit55vnls the car reduces its speed unifogj21d gog4 ,ugv6m3v y6+czl l;thmy. rmly from 90km/h to 60km/h The tires have a diameter of 0.90 m. (a) What was the angu4 yg16vm3olh 2+dyg vmc; gzt6j.ug ,llar 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