The distance between Earth and the Moon is 3.84 108 m. A pulse of laser light aimed at the Moon that bounces back to Earth undergoes a round-trip time of about
A) zero seconds.
B) less than 1 second.
C) two and a half seconds.
D) three seconds.
Question 2
Compared with the speed of light in a vacuum, the speed of light in the empty space between molecules in glass is
A) more.
B) the same.
C) less.