Question

How does an astronomical unit differ from a light-year?

Answer 1

The difference between the light-year and the astronomical unit is that the light-year is the distance of light that travels in one year and the astronomical unit is the average distance between the earth and the sun.

Complete step by step answer:
Consider the term light-year. A light year is a distance unit. It is the measure of the distance of the light photon that travels in one year. It is denoted by the term $Ly$. The light-year value is constant. The branch of physics that deals with the study of the composition and the evolutions of stars and planets are known as Astrophysics. According to astrophysics, the light-year is the term that is used to measure the distance between two astronomical planets.
The light can travel at a velocity of $3,00,000km$ per second. Therefore, in a year the light can travel about $10$ trillion kilometers. Let us see the conversion of the light year.
The conversion of one light-year into a kilometre can be expressed as,
$\Rightarrow ly = 9.4607 \times {10^{12}}km$
Similarly,
One light-year in miles is equal to $5.88 \times {10^{12}}miles$
One light-year can also be expressed in the astronomical unit that is equal to $63241AU$.
Coming to the term astronomical unit. The unit that is used to measure the larger distances in the solar system is known as the astronomical unit. Basically, the distance between the sun and the earth can be measured with the help of this unit. Approximately $150$ billion meters is the distance between the sun and the earth.
With all the above-given information, this is how the astronomical unit differs from a light year.

Note:
Do not get confused between the term’s astronomical unit and the light-years. Both are the units that are used to measure the distances. It approximately takes $500$ seconds for light to reach the earth. Therefore, to travel $1AU$ it takes approximately $500$ seconds.