After a tornado, you decide to go check on your mother\'s house. You start driving down an 11.0 (from the horizontal) hill, when you notice a fallen tree blocking the road. You slam on the brakes and, as a result, your 1670 kg car starts skidding. The coefficient of kinetic friction between the tires and the road is 0.600. 

(a) Calculate your car\'s acceleration while skidding. 

(b) How long does your car take to come to a complete stop, knowing that initially it was moving at 50.0 km/h?