I found an answer from www.britannica.com

optics | History, Applications, & Facts | Britannica

Optics, science concerned with the genesis and propagation of light and with the ... in all directions at the speed of light, each new wave being merely the envelope ... image separation at the focal length of the objective, the light- gathering lens. ... and 6563 angstroms (the angstrom unit, abbreviated Å, is 10^{− 8} centimetre), ...

For more information, see optics | History, Applications, & Facts | Britannica

I found an answer from www.homeschoolmath.net

Speed, Time, and Distance Problems Worksheet Generator

Easy speed, time, and distance worksheet 1: How far can it go or how long does the trip take - using whole or half ... Find the average speed: time is given to the fourth of an hour. ... Find the average speed: problems involve conversion of a time unit ... Time units. Express time in hours and minutes. fifteen-minute increments

For more information, see Speed, Time, and Distance Problems Worksheet Generator

I found an answer from www.quora.com

The metre is defined as the distance travelled by light in 1 ...

Speed of light itself is reprsented using units - metre/sec…then how we can define metre ... Why didn't people choose some easier number such as 1/ 300,000,000 ... If we take the speed of light to be 300,000,000 m/s, and use it to define a metre ... This is approximately the distance between the earth and moon and is hence, ...

For more information, see The metre is defined as the distance travelled by light in 1 ...

I found an answer from en.wikipedia.org

List of unusual units of measurement - Wikipedia

This standard made the historical metre 0.0197% longer than the modern standard metre, which is calculated based on the distance covered by light in a vacuum ...

For more information, see List of unusual units of measurement - Wikipedia

Given that

Speed of the light in vacuum is unity = 1 units/second

Time taken by the light t=8\min\ 20s

= 8 * 60 + 20 = 500 seconds

Step 1: Finding the distance between the sun and earth

Formula: \text{ Speed } = \frac{\text{ Distance }}{\text{ time }}

\text{ Distance } = \text{ Speed * time }

\text{ Distance } = 1 \text{ units/sec } * 500 sec

\text{ Distance } = 500 units

Hence, distance between the sun and earth 500 units