A plane was flying at an altitude of 30,000 feet when it began the descent toward the airport. The airplane descends at a rate of 850 feet per minute.

a. What is the function rule that describes this situation?
b. What is the altitude of the plane after it has descended for 8 minutes? Show
your work.
c. Usethefunctioninpartatodeterminehowlongittakesfortheplaneto
land if it descends at a continuous rate.
Prentice Hall Algebra 1 • Teaching Resources

1 answer

a) new altitude x = 30,000 - 850.t
b) x = 30,000 - 850.8
x = 30,000 - 6,800
x = 23,200 ft
c) x = 30,000 - 850.t
new altitude is 0 ft :
850.t = 30,000
t = 30,000 / 850
t = 35.29 min