Answer:
<em>The plane landed after 9.4 minutes.</em>
Step-by-step explanation:
<u>Function Modeling</u>
The initial altitude of a plane arriving at JFK International Airport is 30,000 ft.
It then began its descent at a rate of 3,200 feet per minute.
Let's call t the number of minutes since the descent started. If each minute the plane descends 3,200 feet, then after t minutes it descends 3,200t.
This must be subtracted from the initial altitude, thus the altitude H is written as:
H = 30,000 - 3,200t
When the plane landed, its altitude was H=0, thus:
0 = 30,000 - 3,200t
Adding 3,200t:
3,200t = 30,000
Dividing by 3,200:
t = 30,000/3,200
t = 9.375 minutes
Rounding to the nearest tenth:
The plane landed after 9.4 minutes.
