If the speed of light is 3x10^8m/s and the distance around the earth is 4.5x10^4 km and a plane could travel at half a speed of light, how long would it take for the plane to fly around the earth twice?

Answer 1

d = 9 * 10^7 meters

time = distance/speed

= 9 * 10^7 meters/ 1.5 * 10^8 m/s

= 6 * 10^-1

= 0.6 seconds

That sounds like very little
but if you are looking at high frequency radio signals, that can be a huge difference in phase between the wave coming to you and the wave reaching you around the earth :)

Answer 2

Thanks

Answer 3

You are welcome.

Answer 4

but the questions says twice. you have just calculated once.