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SurfaceUnits
04-16-11, 10:54 AM
What is the speed of the Earths rotation?

At the equator, the circumference of the Earth is 40,070 kilometers, and the day is 24 hours long so the speed is 1670 kilometers/hour ( 1070 miles/hr). This decreases by the cosine of your latitude so that at a latitude of 45 degrees, cos(45) = .707 and the speed is .707 x 1670 = 1180 kilometers/hr. You can use this formula to find the speed of rotation at any latitude.


Go to http://www.travelmath.com/city/ and under Travel Calculator select latitude/longitude and input your location

take that latitude and go to google (https://encrypted.google.com/) and input cos( ) with your latitude

multiply your locations cosine x1670 to get speed in kph /1.609 to get mph


this explains why your dvd writer reaches its maximum burn speed the closer the laser gets to the outer edge of the disc

Insomniac
04-16-11, 04:24 PM
976.282705

You can also google:

cos(your_latitude) * 1670 km/h to mph

And get it in MPH from the latitude. (I couldn't find a function to get the latitude for your zip code.)