Question

An airplane flying at an altitude of 10,000 feet passes directly over a fixed object on the ground. One minute later, the angle of depression of the object is 42°. Approximate the speed of the airplane to the nearest mile per hour.

Answer 1

126 miles per hour

Explanation:

We can draw a triangle and we can use trigonometry to write:

`a=(10,000)/(Tan(42))=11,106.13`

Where a is the distance plane flew in 1 minute

Since, 11,106.13 FEET in 1 MINUTE, to get in hours, we multiply by 60:

11,106.13 * 60 = 66,367.51 feet per hour

Now, to get in miles per hour, we divide by 5280 [5280 feet = 1 mi]

66,367.51 / 5280 = 126.21 miles per hour

To the nearest mph, it would be 126 miles per hour