Answer:
The range of time it would take the plane to be in the instructed area is 2.5 minutes to 4 minutes.
Step-by-step explanation:
The given parameters are;
The current altitude of the plane = 33,000 feet
The required altitude of the plane = Below 31,000 or above 35,000 feet
The average climbing speed of the plane = 800 feet per minute
The average descending speed of the plane = 500 feet per minute
The difference in the current and required altitudes are;
For climbing we have 35,000 feet - 33,000 feet = 2,000 feet
For descending we have 33,000 feet - 31,000 feet = 2,000 feet
Speed = Distance/Time
∴ Time = Distance/Speed
Based on the climbing and descending rate, we have;
The time it would take to climb 2,000 feet is t = 2000 feet/(800 feet/minute) = 2.5 minutes
The time it would take to descend 2,000 feet is t = 2000 feet/(500 feet/minute) = 4 minutes
The range of time it would take the plane to be in the instructed area is therefore;
Time for descending to time for ascending, which is 2.5 minutes to 4 minutes.
The range of time it would take the plane to be in the instructed area = 2.5 minutes to 4 minutes.