Trouble with Physics Homework?

Question

Speed of light in a vacuum is about 3.00 x 10^8 m/s , determine how many kilometers a pulse from a laser beam travels in exactly one hour.

Answer 1

First, it is important to know that DISTANCE = VELOCITY times TIME.

Second, you know that light travels 3.00 x 10^8 meters in a second.  To find out how far light travels in an hour, you need to multiply the speed of light by the amount of seconds in an hour.

Distance = (3.00 x 10^8 m/s)*(60 seconds/minute)*(60 minutes/hour)

Distance = 1.08 x 10^12 meters

Third, it is important to know conversion factors.  There are 1000 meters in 1 kilometer, so to convert from meters to kilometers, you divide the distance in meters by 1000, or multiply by 1/1000

Distance = (1.08 x 10^12 meters)*(1 kilometer/1000 meters)

Distance = 1.08 x 10^9 kilometers, or 1.08 billion kilometers.