Question

Is light year a unit of time or length?
Plz answer me in correct way because tomorrow is my physics exam plz plz plz plz ​

Answer 1

Answer:

A light-year is a measurement of distance and not time (as the name might suggest). A light-year is the distance a beam of light travels in a single Earth year, or 6 trillion miles (9.7 trillion kilometers).

On the scale of the universe, measuring distances in miles or kilometers doesn't cut it. In the same way that you may measure the distance to the grocery store in the time it takes to drive there ("The grocery store is a 15-minute drive away"), astronomers measure the distances of stars in the time it takes for light to travel to us. For example, the nearest star to our sun, Proxima Centauri, is 4.2 light-years away.