how would u find the radius of the earth?

Question

what if there were no sources to help u? (like the internet)

Answer 1

Which radius?

The earth is not a sphere, it is an oblate spheroid that has varying radii at different points. The radius at the equator is longer than that at the poles. If you want to find the radius at the equator without sources, you can try to estimate the circumference of the earth based on it's rotational velocity. (Think about time zones across the U.S.) Once you have a circumference, it's simple arithmetic to calculate the radius.

Answer 2

So now you appreciate how smart the guys like Galileo, Copernicus, and Ptolemy were. They were able to do this more than a thousand years ago (perhaps with the help of extra-terrestials, eh?). Just joking. They did geometrical triangulations to calculate the diameter of the earth. They designated several distinct observation points (reference locations) on the earth's surface. The distances between these distinct points were known. From each of these observation points, they recorded the changes in the positions of the stars at different time intervals (as the earth rotates on its axis). From the changes in the stars' recorded positions, the duration of the time intervals, and the distances between the observation points, they were able to calculate the earth's diameter by geometrical methods. Of course, they assumed the earth to be a perfect sphere in their calculations. But the result of their calculations weren't so far off from our present-day figures.

Answer 3

The IUGG value for the equatorial radius of the Earth is 6378.137 km (3963.19 statute miles ), giving an equatorial circumference of 40,075 km (24,901.5 miles

Answer 4

That would depend on whether or not you are using
a 3-dimensional Earth .

Answer 5

The same way Ptolemy did it-geometry.

Answer 6

try msn.com or yahoo.com or google.com