Question: What is the distance traveled by a plane that goes around the earth at the latitude of 60 degrees?
Answer: The formula for the distance traveled around the earth at a particular latitude is
C=2 x pi x r x cos (a)
pi is 3.14159,
r is the radius of the earth which is 6278 kilometers,
cos(a) is the the cos of the angle of latitude.
Note that at the equator the latitude is 0 degrees and the cos(0) is 1 so the distance traveled is 2 x 3.14159 x 6278, which is 40,074 km.
Note also that at the poles the angle of latitude is 90 degrees, the cos(90)=0 and the distance traveled is 0.
The question asks for the distance traveled at a latitude of 60 degrees. The cos(60) is 0.5.
So at 60 degrees latitude the distance traveled around the earth is 20,037 km.
Information on this formula was obtained from a Department of Energy Web site: See citation below:
Richard E. Barrans Jr., Ph.D.
PG Research Foundation, Darien, Illinois
The answer was posted on a web site created by National Argonne Labs
Here are web sites providing some information on cities that are a latitude of 60 degrees north
Interestingly there is no land at 60 degrees south