Light and radio waves travel through a vacuum in a straight line at a speed of very nearly 3.00 ' 108 m/s. How far is light year (the distance light travels in a year) ?

We need to calculate the number of seconds in one year. time = (365 days) (24 hours/day) (3600 seconds/hour) time = 31536000 seconds We can calculate the distance that light travels in this many seconds. distance = speed x time distance = (3.00 x 10^8 m/s) (31536000 seconds) distance = 9.46 x 10^{15} meters A light year is 9.46 x 10^{15} meters