Explanation:
9. The height at the 4.5-hr mark is 16,000 ft. At the 5.0-hr mark, the plane has landed and thus, it's altitude is zero. The change in altitude 
 is 0 - 16,000 ft or -16,000 ft. The change in time
 is 0 - 16,000 ft or -16,000 ft. The change in time 
 is 5 hr - 4.5 hr or 0.5 hr. So the rate of change of the altitude is
 is 5 hr - 4.5 hr or 0.5 hr. So the rate of change of the altitude is

10. The initial temperature is 58°F and the final temperature is 76°F, therefore 
 The time elapsed is
 The time elapsed is 
 The rate of change of the temperature is
 The rate of change of the temperature is
