The tires of a car make 45 revolutions as the car reduces its speed uniformly from 100 km/h to 30 km/h. The tires have a diameter of 0.80 m.
(a) What was the angular acceleration in rad/s^2?
(b) If the car continues to decelerate at this rate, how much more time is required for it to stop in seconds?
Please explain thoroughly how to do this.