# Longitude

Discussion in 'Earth Science' started by Nebula, Jan 19, 2003.

1. ### NebulaOccasionally FrequentRegistered Senior Member

Messages:
906
How do you convert longitude? Here are two questions from my homework that I'm really having trouble figuring out:

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45. The longitude of Moscow is +37°37.002'. What is this in decimal degrees?

a. +37.617°.
b. +37.37002°.
c. +37.7002°.

I know the answer is +37.617 (hehe, I found an online converter), but I'd like to know how it's done.

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49. The longitude of Vancouver is -123.08°. What is this in degrees and minutes?

a. -123° 8'.
b. -123° 480'.
c. -123° 4.8'

I know you need to convert the fractional part (.08°) into minutes of arc, but I can't figure out how, and my textbook doesn't even touch on this subject

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So any help would be greatly appreciated! Aside from the slight difficulty I'm having, I love the class!

-Kyle

3. ### chrootCrackpot killerRegistered Senior Member

Messages:
2,350
Well, this doesn't really belong in the Astronomy section... but whatever. A degree of arc is equivalent to 60 minutes of arc (abbreviated with a ' mark); and a minute of arc is equivalent to 60 seconds of arc (abbreviated with a " mark).

0.08 degrees * 60 arcminutes / degree = 4.8 arcminutes

0.8 arcminutes * 60 arcseconds / arcminute = 48 arcseconds

0.08 degrees = 0 deg 4' 48"

- Warren