6. The position of a car travelling along a straight road is given by x(t), where t is in hours and x is in miles. Originally, the car is travelling at 80 miles per hour, but at time t = 0 and position r = 0, the driver sees a police car and applies the brakes. The resulting acceleration is at a rate of -10t miles per hour squared (mile/ hr?). a)(4) how soon will the car be travelling at 40 miles per hour? Nork - distance time b)(4) how far will be car travel in the interval between when she is driving at 80 and when she reaches 40? 7. (4) Let t be time in minutes, and suppose air pressure during a one hour interval is given by P(t) = t(t + 2). Compute the average pressure over that time interval