2006-08-22 17:18:20 · 6 answers · asked by Sarah 1 in Science & Mathematics ➔ Physics
6,378.135 km
3,963.189 mi
Aloha
2006-08-22 17:21:49 · answer #1 · answered by Anonymous · 2⤊ 0⤋
The Earth's equatorial radius, or semi-major axis, is the distance from its centre to the equator and equals 6,378.135 km (â3,963.189 mi; â3,443.917 nmi).
The Earth's polar radius, or semi-minor axis, is the distance from its center to the North and South Poles, and equals 6,356.750 km (â3,949.901 mi; â3,432.370 nmi).
Qudratic: It is this radius that would be used to approximate the ellipsoid's average great ellipse (i.e., this is the equivalent spherical "great-circle" radius of the ellipsoid).
For Earth, Qr equals 6,372.795477598 km (â3,959.871 mi; â3,441.034 nmi).
Authalic ("equal area") mean radius is approximately 6,371.005076123 km (â3,958.759 mi; â3,440.067 nmi). This number is derived by square rooting the average (latitudinally cosine corrected) geometric mean of the meridional and transverse equatorial, or "normal" (i.e., perpendicular), arcradii of all surface points on the spheroid
Merdianol 6367.446988834 km (â3,956.548 mi; â3,438.146 nmi).
The average of all of these then becomes
3,958.761 miles
2006-08-22 17:29:02 · answer #2 · answered by Anonymous · 0⤊ 0⤋
6,378.14 km
For more interesting data about Earth visit http://solarsystem.nasa.gov
2006-08-22 17:26:01 · answer #3 · answered by jorge f 3 · 0⤊ 0⤋
6378 Km but it varies a bit depending on whose numbers you use. This is the IUGG value.
Doug
2006-08-22 17:24:03 · answer #4 · answered by doug_donaghue 7 · 0⤊ 0⤋
roughly 4000 miles
2006-08-22 17:20:40 · answer #5 · answered by Freddy 3 · 0⤊ 0⤋
pls refer to clark's tables it is around 6350 kms
2006-08-22 18:44:47 · answer #6 · answered by Anonymous · 0⤊ 0⤋