The distance s (in feet) covered by a car t sec after starting is given by the following function. s = −t3 + 11t2 + 20t (0 ≤ t ≤ 6) Find a general expression for the car's acceleration at any time t (0 ≤ t ≤ 6). s ''(t) = Correct: Your answer is correct. At what time t does the car begin to decelerate? (Round your answer to one decimal place.) t = sec