A laser produces a beam of light.  All light travels in air at a constant speed of approximately 300 million meters per second. Therefore, a distance can be measured accurately by calculating the time it takes for a laser beam to travel between two points, such as A and B. The beam is timed with precise electronic equipment, calculating and accurately displaying the correct distance.

The equation used to calculate the distance is:

Distance (in meters)

= Time (seconds) (Speed of Light in Air(meters/second)

^{You are interested in experimenting to find out the time in seconds that it takes for the laser beam to travel over a measured distance of 3000 meters. Solve for this problem.}

^{Time (in seconds) = Distance (in seconds) / Speed of Light in the Air (m/sec)}

^{Time = 3000 / 300,000,000}

^{Time = 0.00001 seconds}

^{The time for the laser beam to travel from Point A to Point B is 0.003 seconds. What is the distance between the two points ?}

^{Estimate the answer:}

^{Less than 100,000  meters
Between 100,000 and 500,000 meters
Over 500,000 meters}