Answer
A beam of light travels 30 centimeters in $1~ns$
Work Step by Step
We can find the distance a beam of light travels in $1~ns$:
$d = c~t$
$d = (3.0\times 10^8~m/s)(1.0\times 10^{-9}~s)$
$d = 0.30~m = 30~cm$
A beam of light travels 30 centimeters in $1~ns$.
