The speed of light is 3.0×10
km/s, and it takes 1.3 seconds
for light to travel from the Moon to Earth. Based on this
information, what is the distance from the Earth to the Moon?
There approximately 100 billion stars in our galaxy. If there
100 billion observable galaxies in our universe, what is a
reasonable estimate for the total number of stars in the
is the distance that light travels in an hour.
How far is this, in kilometers? (Recall that the speed of light is