function questions

Question

Write a function that could be used to calculate the altitude of a plane arriving at JFK

International airport which was cruising at an altitude of 30,000 before it began its descent at a rate

of 3,200 feet per minute. How many minutes would it be before the plane landed. Round your answer to the nearest tenth.

Answer 1

Hello, Jeff,

Let x be the minutes the plane flies after reaching the 30,000 foot level. We'll assume "landing" means zero feet. To find the time required to get to zero feet, take the rate of decent (3200ft/min) times the time (x), in minutes and set it equal to 30,000 feet.

30,000ft = (3200ft/min)*x

x = 9.375 minutes, or 9.4 to the nearest tenth.

Bob