How long does it take a radio signal to travel 172 km from a transmitter to a receiving antenna?

Question

I tried using n=c/v with the n of air = 1.0029 and then using t = v/d with 172000 m, but that didn't work. It also doesn't work with n = 1... Please help!

Answer 1

t = distance / (speed / index of refraction)).

t = 172km / (299792.458 / 1.0029) = 5.7539406144767E-04

seconds (notice I divided C by 1000 to convert to km/s and used the refractive index for air that you gave, I don't know what it actually is)

by the way, in case you didn't know, the "e-04" at the end means *10^-4.  Rounded off it would be .00057 seconds