Question

find the minimum height above the surface of the earth so that the pilot at point a can see an object on the horizon at c 125 miles away. assume the diameter of the earth to be 8000 miles.

Answer 1

Draw a diagram, with a line from the horizon to the pilot.

If the pilot is at height h miles, then

(8000+h)^2 = 125^2 + 8000^2

Answer 2

2 miles