

Earth's Rotational Speed
Name: Mary
Status: Other
Age: 30s
Location: N/A
Country: N/A
Date: N/A
Question:
How many miles per hour does the earth rotate?
Replies:
The rotation speed of the earth depends on where you happen to be. If
you stand directly on the north or south pole, it is essentially zero.
After 24 hours you would have rotated one complete turn and be facing
the way you started. There is no tangential speed. At the equator 
where one would travel one complete lap of the earth in 24 hours  your
speed would be about 1000 miles per hour. (assuming a 24000 mile
circumference for the earth). As you travel north or south from the
equator towards the poles your tangential speed decreases. It is a bit
like a carnival ride.
Larry Krengel
That depends on where you are, doesn't it? I mean, if you are
standing at the North Pole, then you are spinning in place and not
going anywhere at all. Same at the South Pole. In between you can
figure it out by noting that you go once around in a circle every 24
hours. The extra information you need is how the Earth's
circumference varies with latitude. The answer from trigonometry is C
= 2 x Pi x R x Cos((Pi x L)/180), where C is the circumference in
miles, Pi is 3.141592653..., R is the radius of the Earth, which is
3963 miles, and L is the latitude in degrees (for example Los Angeles
is at latitude 34 degrees North).
Hence if you live in Los Angeles, you go around in a circle 2 x Pi
x R x Cos(Pi x 34/180) = 20643 miles in circumference each 24 hours,
which means you are speeding along at 20643/24 = 860 miles/hour.
Grayce
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Update: June 2012

