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What is the Iinear speed of a point on Earth's equator? What if the point was at latitude -15.0° ?

1 Answer
Aug 6, 2016

Answer:

At the equator, linear speed with respect to the polar (day/night spin ) axis is 463.82 meter/s = 1521.8 feet/s, At latitude #15^o N and 15^o S#, this speed is 447.77 meter/s = 1469.1 feet/s.

Explanation:

In the day-night spin, any point on the Earth moves around Earth's

axis in its latitude circle.

Speed = (distance traveled in a second)/second..

The circumference of the equator = #2 pi X 6378# km.

The number of seconds in a day = 24 X 3600

So, at the equator, speed = #( 2 pi X 6378 ) / ( 24 X 3600 )# km/s =

0.46382 km/s = 463.82 meter/s = 1521.8 feet/s.

At #+-15^o# latitude Earth's ( a little less than equatorial )

radius is

6374.5 km, nearly.

The latitude-circle circumference

= #2 pi X 6374.5 X cos 15^o# km.

So, the speed is (#2 pi X 6374.5 X cos 15^o#)/(24 X 3600)=

0.44777 km/s = 447.77 meter/s = 1469.1 feet/s
.
Thanks to Johannes C for pointing to the error in the unit km,

used for meter, in my earlier edition...