## College Physics (4th Edition)

(a) $1~light~second = 3.0 \times 10^8~m$ (b) $v = 1 ~light~second~per~second$
(a) We can find the distance light travels in one second: $d = v~t$ $d = (3.0\times 10^8~m/s)(1.0~s)$ $d =3.0\times 10^8~m$ $1~light~second = 3.0 \times 10^8~m$ (b) We can find the speed of light: $v = \frac{distance}{time}$ $v = \frac{1~light~second}{1~second}$ $v = 1 ~light~second~per~second$