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1) How many AU make up a light-year?

2) What ia an astronomical unit (AU) in miles and kilometers? Why is it useful for understanding the distances to planets?

2 Answers

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Answer:

1) 63241 AU make a light year.

2)
1.495x10^(8)km, 92914853miles

The astronomical unit gives a simple way to compare distance between planets and the Sun, using the distance from the Sun to Earth as an started point.

Step-by-step explanation:

1) How many AU make up a light-year?

A light year is the distance that light can travel in one year

The speed of light has a value of
3x10^(8)m/s

That can be express in units of kilometers and years:


3x10^(8)m/s \cdot (1km)/(1000m) --
300000km/s \cdot (31536000s)/(1year) --
9.4608x10^(12)Km/year

Therefore, the distance can be found by means of the equation for average velocity.


v = (x)/(t)


x = v \cdot t (2)

Then, t will be equal to 1 year (
t = 1 year)


x = (9.4608x10^(12)Km/year)(1year)


x = 9.4608x10^(12)Km

However, an astronomical unit is defined as the distance between the Earth and the Sun (
1.495x10^{8]km).

Therefore, to know how many astronomical units make a light year:


(9.4608^(12)km)/(149597870km) = 63241

Hence, 63241 AU make a light year.

2) What is an astronomical unit (AU) in miles and kilometers? Why is it useful for understanding the distances to planets?

As in was already said, an astronomical unit has a value of
1.495x10^{8]km

Then, it can be express in units of miles:


1.495x10^(8)km (1mile)/(1609km)
92914853miles

The astronomical unit gives a simple way to compare distance between planets and the Sun, using the distance from the Sun to Earth as an started point.

User Frishi
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3.7k points
3 votes

Answer:..

1.One light-year = 63,240 AU

2. It’s about 93 million miles (150 million km),or

one astronomical unit (AU) = 92,955,807 miles (149,597,871 km).

User Dchucks
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3.3k points