The moon is about 3.8x10^8m from Earth. Traveling at the speed of light, 3.0x10^8 m/s, how long does it take a laser beam to go from Earth to the moon and back again?

Question

isaiah.feynman · Answer

3 seconds.

anonymous · Answer

really, how were you able to figure that out, or what was the formula used?

isaiah.feynman · Answer

Its an easy calculation but I didn't do it because I listen to physicists give talks sometimes (You can learn lots of quick facts from that). So I saved myself few seconds of calculating. But the formula is simply; Time=distance/speed.

anonymous · Answer

oh nice! ok, and then it would be multiplied by two because of it going back again right?

isaiah.feynman · Answer

Yes, lol I just quickly punched my calculator and got 2.5 seconds which is not too far from the precise value of 3 seconds.

anonymous · Answer

ok that's what I thought I just wanted to make sure! thank you so much that was a lot of help.

isaiah.feynman · Answer

No probs!

isaiah.feynman · Answer

@Saeeddiscover that doesn't happen in my universe. :P