what is the diameter of the earth?
147652
It varies a bit since the earth isn't exactly round, but an average of 12755 km over the equator and about 12155 km over the poles is about right I think.
265377
The average distance from the Moon to the Earth is 384,403 kilometres (238,857 miles). The Moon's diameter is 3,476 km (2,160 miles).
931645
first answer was close to right.\n\nthere is one qualification that seems need.\n(do this all in meters for easyness of calculation)\n\nR = radius of earth = 6400 km = 6.4 * 10^6 meters\nd = distance to horizon in meters\nh = height in meters\n\nSimilar triangles:\n\nR / d  = d / 2h\n\nd^2 = 2Rh\n\nd = sqrt (2Rh)\n\n....  works pretty well for small "h"\n\neg 2 meters height =>\n\nd = sqrt (2 * 6.4 * 10^6 * 2 ) = sqrt (25.6 * 10^6) \n=5.06 km\n\n[[ online calculator gives 5.5 km ]\n\nmine's a LOT easier to use ...\n\nI use "2h" instead of "h" for similar triangles\nbecause of discrepancy of right angle at the\nradius from eearth-center to observer and\nr-a from earth-center to distant object.\n[intersection happens "h" below earth surface]\n\nthat sounds confusing but I can't draw a picture\n\nmy eqn is easiest possible tho ..
540447
Let's just talk about Earth. The earth's diameter is 12756 km. Its circumference is pi x 12756 = 40074 km. The earth spins 1 round in 24 hours. That's 1700 km/h, or 472 m/s. If it rotates in an OPPOSITE direction, it's like the Earth is rotating at 944 km/s and suddenly stops. What happens? You fly through the air at 944 km/s. All the houses fly through the air at 944 km/s. Whole forests fly at 944 km/s. Even whole mountain ranges and mountain tips fly at 944 km/s. The ocean's waters fly backward at 944 km/s. Talk about a uber tsunami. I don't know what the friction of air against these object would do to them. Can anyone solve that? Even the Earth's crust might become detached with its outer mantle, I think. Lava breaks out everywhere, global earthquakes... In short: All hell breaks loose. Man, that's even worse than the Death Star. Superman actually does that to Earth in one of his movies. He's a major nut!
724249
3.14 inch !! Surprised No? Here is te answer, when we  tie apiece of string around the earth so that it touches all the way around means , we are calculating the circumference of the cross section of the earth.\n\nLet R be the radius of the cross section which is a circle, then coircumference will be\n\n2(Pie)R\n\nNow to get the string 1/2 an inch away from the surface, we need to increase the radius by 1/2 an inch, Thus the new circum ference will be\n\n2(pie) x(R+1/2)\n\n= 2(Pie)R + 2(Pie)/2\n\n=2(Pie) R + Pie\n\nDifference in the new circumference and old will be the difference in the length of the string which will be equal to\n\n2(Pie)R + Pie -2(Pie)R = Pie\n\n\nand value of Pie is 22/7 =3.14, Since we have taken inch as our Unit, Answer will be 3.14 inches more string would be required.
69500
The circumference of the earth at the equator is 24,902 mi / 40,076 km.
619435
Hi ... The diameter of Mars is 4228.4 Miles ... follow the link below for loads more info ... Hope this helps !!!
150417
The apparent diameter of a celestial object is the diameter measured by an observer at a specific distance from the object. The smaller the distance between the observer and object, the greater the apparent diameter. Apparent diameters are often expressed as angular diameters.
478701
Equatorial diameter 6,804.9 km (4228.4 Miles)\n(0.533 Earths)\nPolar diameter 6,754.8 km (4197.2 Miles)\n(0.531 Earths)\nOblateness 0.007 36\nSurface area 1.448×108 km2 (55.907 Million Square Miles)\n(0.284 Earths)\n\n\n"Mars-5-inch-thing" Sure... but in which category of questions are we?
21355
Equatorial Diameter: 7937 miles\nPolar Diameter: 7900 miles\n\nThe equatorial diameter is greater because the Earth is  spinning on it's axis (at about 1000 mph at the equator) which greats a centrifugal force pulling away from the center of the planet. This effectively lessens the gravitational pull at the equator and the equatorial regions of the planet bulge out.\n\nYou'll also find some other interesting solar system data at the site below.
855234
Earth rotates 360 degrees in 24 hours or 15 degrees per hour that it goes through 0,5 degrees of rotation in two Minutes\n\nClick on the URL below for addition information concening the earth rotation. See Item 17\n\nhelios.gsfc.nasa.gov/qa_earth.html \n\n. - - - - - - - - - - - - - - - - - - - - - - - - - -\n\nThe diameter is 7926 Miles\n\nCircumference\n\nc = d π\n\nc = 7916(3.141592654)\n\nc = 24900.26337 miles\n\nClick on the URL below for additional informatio concerning the circumference of the earth\n\nwww.lyberty.com/encyc/articles/earth.html \n\n- - - - - - - - - - - - - - - - - - - - - - - - \n\nSolving for earth rotation per degree in miles\n\n24900 ÷ 360 = 69.16666667\n\nThe earth  rotates 69.2 Miles for each degree of rotation. Rounded to one decimal point.\n\n- - - - - -s-
350355
Earth is an oblate spheroid, resembling a sphere flattened at the poles.\n\nThe volume of an oblate spheroid is\n\n    V = 4/3 X 3.14 X a^2 X b\n\nwhere π is the mathematical constant pi, and a and b are the equatorial and polar radii.\n\nSubstituting a = 6,378,135 m and b = 6,356,750 m\n\nThe Huge EarthThe mean radius of the earth is approximately 6.4 million meters (exact = 6.37 x 106 m). Its volume is then:\n\n(4/3) x 3.14 x 64000003 m3\n\nThis comes to 1,097,509,500,000,000,000,000 cubic meters.
24866
The Earths orbit is 93 million miles from the sun, so the diameter of the earths orbit is 186 million miles.\n3.14 x 186 million = 584 million miles for 1 orbit. This is an approximate value.
1183745
Mars is much smaller than Earth.  About 1/2 the diameter (0.53), and 1/10 of the mass (0.107) of the Earth.\n\nHere's a great set of illustrations showing the relative sizes of all the planets, and the sun.\n\nhttp://www.comagz.com/webmagazine/story/proportions_how_small_we_are
419674
The Earth is approximately 25,000 miles in diameter at the equator, and it spins once in about 24 hours.  So, at the equator, the Earth is spinning about 1000 miles per hour.  However, if you live in the US, the Earth is moving much slower-about 70% the speed depending on your exact latitude-and slower as you go north or south from the equator.
937052
The Sun is roughly 100 times the diameter of Earth, which is about one million times the volume.
14152
The circumference of the earth at the equator is 24,901.55 miles (40,075.16 kilometers).\n\nBut, if you measure the earth through the poles the circumference is a bit shorter - 24,859.82 miles (40,008 km). This the earth is a tad wider than it is tall, giving it a slight bulge at the equator. This shape is known as an ellipsoid or more properly, geoid (earth-like).