Converting light years to meters and miles

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SUMMARY

A light-year is defined as the distance light travels in one year, calculated using the speed of light, which is 3.00 x 108 m/s. The correct conversion of a light-year results in approximately 9.46 x 1015 meters. To convert this distance into miles, one must divide the meter value by 1609.34, as 1 mile equals 1609.34 meters. The discussion emphasizes the importance of calculating the total number of seconds in a year to derive the distance accurately.

PREREQUISITES
  • Understanding of the speed of light (c = 3.00 x 108 m/s)
  • Knowledge of unit conversions between meters and miles
  • Ability to calculate time in seconds for a year
  • Familiarity with scientific notation (e.g., 1015)
NEXT STEPS
  • Learn how to calculate the number of seconds in a year for distance conversions
  • Research the concept of light-years and their significance in astronomy
  • Study unit conversion techniques, specifically from meters to miles
  • Explore scientific notation and its applications in physics
USEFUL FOR

Students studying physics, educators teaching astronomy concepts, and anyone interested in understanding astronomical distances and unit conversions.

TrimHopp
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Homework Statement



A light-year is the distance that light travels in one year. Find this distance in both miles and meters.

Homework Equations



Speed of light (c) = 3.00x10^8 m/s

The Attempt at a Solution



10^15 m/s
__________
3.00x10^8 m/s

That is to find meters...I think I can only find miles after I find meters by dividing that answer by 1609m

Thanks.
 
Last edited:
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I think google could help you with this.
 
TrimHopp said:

Homework Statement



A light-year is the distance that light travels in one year. Find this distance in both miles and meters.

Homework Equations



Speed of light (c) = 3.00x10^8 m/s

The Attempt at a Solution



10^15 m/s
__________
3.00x10^8 m/s

That is to find meters...I think I can only find miles after I find meters by multiplying that answer by 1609m

Thanks.

Where did 1015 m/s come from? and what are you doing/trying to do?

You were told how far light goes in a second, how about a minute? Then how about an hour? a day? 365.24 days? [a year]

Once you know how many meters, I wouldn't be multiplying by 1609. I don't think anything is more miles away from something that it is meters away from something! The end of my street is about 120 m away, but it is far less than even 1 mile.
 
Right peter, I meant divide. Thanks for that.

In the book where I get the problem from, it says 1 light year = 9.46 Pm (P being peta (15) and m being meters). I thought that was 10^15?
 
TrimHopp said:
Right peter, I meant divide. Thanks for that.

In the book where I get the problem from, it says 1 light year = 9.46 Pm (P being peta (15) and m being meters). I thought that was 10^15?

Yes, but then that makes the length of a light-year 9.46 · 1015 m. But if you know this, why divide by the speed of light? That would tell you the length of time it takes light to travel one light-year, yes?

You are being asked to compute the length of a light-year, given that light travels at (very nearly) c = 3.00 · 108 m/sec . You need to work out the number of seconds in a year. (You may use the distance you looked up as a check...) You then need to convert this value from meters into miles.
 

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