•2. If sunlight takes 8 minutes to travel from the Sun
to the Earth, how long
does moonlight take to travel from the Moon to the Earth? To find this, use information about the relative distance of the moon and the sun which you can find in your text.
•
•I’ve asked you to set this up in terms of
light travel time. We know
that the distance from the Earth to the sun is 1 AU, or about
150,000,000 km. The distance from the Earth to the
moon is in appendix A table A-14, and is 384,000 km. 150 million divided by 384 thousand is 391. So, light will take 1/391 time to travel between the moon and
Earth as it does from sun to Earth.
So the travel time is 8min x 60 sec/min / 391 = 1.2 seconds.