Question

Assume the radius of Earth is 3960 miles and that there areno hills or obstructions. About how far can you see to the horizon from an airplane 5 miles high?

Answer 1

Your line of sight from the plane forms a tangent with Earth (the horizon), this gives you a right-angled triangle with sides of length 3960m and 3960+5=3965m. Using Pythagoras' theorem give the other side as:\[\sqrt{3965^2-3960^2}\approx199m\]

Answer 2

thanks.

Answer 3

No problem.