# Moving west Away from Sun Rise

Discussion in 'Math' started by loosewire, Nov 21, 2009.

1. ### loosewire Thread Starter AAC Fanatic!

Apr 25, 2008
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How fast would you have to move west to keep ahead of sunrise
in east. Assuming you had a clear pathway. With earth rotating
toward the sun.

Last edited: Nov 21, 2009
2. ### jpanhalt AAC Fanatic!

Jan 18, 2008
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909
Depends on the latitude. John

3. ### beenthere Retired Moderator

Apr 20, 2004
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At the equator, it's close to 24,900 miles around the planet. To go that far in 24 hours means you have to move at 1,037.5 MPH. Faster at altitude, as the circumference of your path increases. In geosynchronous orbit, it's 24,900 MPH.

Last edited: Nov 21, 2009

Jul 7, 2009
1,585
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If the circumference of the earth at the equator is C, then the circumference of the earth at latitude θ (i.e., the circle created by a cut by a plane parallel to a plane containing the equator) is $C cos \theta$. Divide that by the period of rotation (say, the sidereal day) and you have the linear velocity you desired. Add in complexities as desired (e.g., nonspherical earth, topography, etc.).

5. ### thatoneguy AAC Fanatic!

Feb 19, 2009
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This speed varies based on latitude and altitude.

At 45 degrees North latitude, the required speed is 731 mph or 1176 km/h.

At 30 degrees North, the speed increases to 896 mph or 1442 km/h.

At the Equator, you would need to be going 1035 mph or 1666 km/h

This is assuming ground level. At altitude, where those speeds can be reached, the difference isn't huge, but you'd need to go a bit faster.