2 of 3 Q - + | Page view A" Read aloud T Add text Draw Highlight Erase | | 6 91 12. Airline travel The following figure shows the position function of an airliner on an out-and-back trip from Seattle to Minneapolis, where s = f (1) is the number of ground miles from Seattle / hours after take-off at 6:00 A.M. The plane returns to Seattle 8.5 hours later at 2:30 P.M. a. Calculate the average velocity of the airliner during the first 1.5 hours of the trip (0 st s 1.5). b. Calculate the average velocity of the airliner between 1:30 P.M. and 2:30 P.M. (7.5 st s 8.5). c. At what time(s) is the velocity 0? Give a plausible explanation. d. Determine the velocity of the airliner at noon (t = 6) and explain why the velocity is negative. 1600 1200- 800 s = f(1) Position (miles from Seattle) 400 Time (hours) 24. Suppose a stone is thrown vertically upward from the edge of a cliff on Earth with an initial velocity of 19.6 m/ s from a height of 24.5 m above the ground. The height (in meters) of the stone above the ground / seconds after it is thrown is s(1) = -4.9~ + 19.6 + 24.5. a. Determine the velocity v of the stone after t seconds. b. When does the stone reach its highest point? c. What is the height of the stone at the highest point? d. When does the stone strike the ground? e. With what velocity does the stone strike the ground? f. On what intervals is the speed increasing? 29-32. Average and marginal cost Consider the following cost functions. a. Find the average cost and marginal cost functions