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(t) is the number of ground miles from Seattle
t 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 ≤ t ≤ 1.5).
b. Calculate the average velocity of the airliner between 1:30 P.M.
and 2:30 P.M. (7.5 ≤ t ≤ 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.