During an Apollo moon landing, reflection panels were placed on the Moon. This allowed Earth-based astronomers to shoot laser beams at the Moon's surface to determine its distance. The reflected...

During an Apollo moon landing, reflection panels were placed on the Moon. This allowed Earth-based astronomers to shoot laser beams at the Moon's surface to determine its distance. The reflected laser beam was observed 2.52 s after the laser pulse was sent. If the speed of light is `3.00 * 10^8` m/s what was the distance between the astronomers and the moon?

Expert Answers
Borys Shumyatskiy eNotes educator| Certified Educator

Hello!

The distance may be obtained from the formula distance = speed * time. The speed of light is given and the time is also given. The only thing we have to take into account is that the laser beam flew the distance from Earth to the Moon twice: there and back.

So the distance between the astronomers and the Moon was about `1/2 * 3.00*10^8 * 2.52= 3.78*10^8(m), `  or `3.78*10^5` km.