Converting light years to meters and miles

In summary, the student is attempting to solve a homework problem from a book that asks for the length of a light-year to be computed. They first need to find the speed of light (c), then convert from meters to miles.
  • #1
TrimHopp
3
0

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:
Physics news on Phys.org
  • #2
I think google could help you with this.
 
  • #3
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.
 
  • #4
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?
 
  • #5
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.
 

1. How do you convert light years to meters?

One light year is equal to approximately 9.461 trillion kilometers, which can be converted to meters by multiplying by 1 trillion. Therefore, one light year is equal to approximately 9.461 quadrillion meters.

2. Can you convert light years to miles?

Yes, one light year is equal to approximately 5.879 trillion miles. This can be calculated by multiplying the conversion factor of 0.621371 by the number of kilometers in a light year (9.461 trillion).

3. Why do we use light years instead of regular units of distance?

Light years are used in astronomy because they represent vast distances that can be difficult to conceptualize in meters or miles. Additionally, the speed of light is a fundamental constant in the universe, making light years a more universal unit of measurement.

4. Is there a formula for converting light years to meters and miles?

Yes, the formula is: 1 light year = 9.461 trillion kilometers = 5.879 trillion miles. This can be broken down further to 1 light year = 9.461 x 10^12 kilometers = 5.879 x 10^12 miles.

5. Can light years be converted to other units of distance?

Yes, light years can also be converted to other units such as astronomical units (AU) or parsecs. An astronomical unit is equal to the average distance between the Earth and the Sun, which is approximately 149.6 million kilometers. One light year is equal to approximately 63,240 AU. A parsec is equal to approximately 3.26 light years.

Similar threads

  • Introductory Physics Homework Help
Replies
8
Views
1K
Replies
12
Views
954
  • Introductory Physics Homework Help
Replies
13
Views
1K
  • Introductory Physics Homework Help
Replies
6
Views
809
  • Introductory Physics Homework Help
Replies
3
Views
779
  • Special and General Relativity
Replies
34
Views
1K
  • Introductory Physics Homework Help
Replies
10
Views
2K
  • Introductory Physics Homework Help
Replies
5
Views
930
  • Introductory Physics Homework Help
Replies
15
Views
1K
  • Introductory Physics Homework Help
Replies
7
Views
1K
Back
Top