Answer:
Part A:
9 Minutes
Part B:
The first method by direct calculation is faster
Step-by-step explanation:
Part A:
The height of the first airplane = 52,200 feet
The rate of descending of the first airplane = 3,100 feet per minute
The rate of ascent of the second airplane from the ground = 2,700 feet per minute
Therefor, we have;
3100 × t = x
2700× t = 52200 - x
∴ 2700× t = 52200 - 3100 × t
5800 × t = 52200
t = 52200/5800 = 9 minutes
Therefore, the time both planes will be at the same height = 9 minutes
Part B:
1) Another method is to determine how long it will take the first plane to land and the second plane to ascend to 52200 feet, then find the ratio of the duration and estimate what time both plane will cover a distance of 52200 feet
2) A third method is to plot the graph of motion and find the point of intersection of the equation of motion of both airplanes
The first method by direct calculation is faster