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is it true that if earth's density wasn't uniform then the gravitational force was half of what it is now? can you give me a mathematical calculation of why that would reduce to half of its current value.thanks
oops! i meant if the density was uniform the gravity was half of its value. are u sure? if yes what does this article say?The earth's density isn't uniform.
Nonetheless, the density distribution of the earth does not influence the gravity at the surface. That's determined solely by the mass and radius.
The earth's density isn't uniform.
Nonetheless, the density distribution of the earth does not influence the gravity at the surface. That's determined solely by the mass and radius.
Vanadium 50 means a density distribution which varies with depth: like that the core shells are more dense that the outer shell. This distribution doesn't affect the gravity outside the earth which is also symmetrical.oops! i meant if the density was uniform the gravity was half of its value. are u sure? if yes what does this article say?
http://www.csr.utexas.edu/grace/publications/press/032007_discovermag.pdf
The article doesn't say anything like that.oops! i meant if the density was uniform the gravity was half of its value. are u sure? if yes what does this article say?
http://www.csr.utexas.edu/grace/publications/press/032007_discovermag.pdf
That's not true, either. Knowing how Earth's gravity varies with latitude and longitude is very important if you want to, for example, accurately predict the motion of a satellite or find a new oil field.The earth's density isn't uniform.
Nonetheless, the density distribution of the earth does not influence the gravity at the surface. That's determined solely by the mass and radius.
While that's true, let's go back to the OP's question.That's not true, either. Knowing how Earth's gravity varies with latitude and longitude is very important if you want to, for example, accurately predict the motion of a satellite or find a new oil field.
We're not talking about the tiny non-uniformities that let one find oil fields, we're talking about factors of two. So while I probably should have had a couple of paragraphs of caveats, the approximation of the earth as a sphere whose density depends only on radius is a pretty good one to answer the OP's question.is it true that if earth's density wasn't uniform then the gravitational force was half of what it is now? can you give me a mathematical calculation of why that would reduce to half of its current value.thanks
In light of the original post which posits that a uniform density would alter Earth's gravity by a factor of two, Vanadium is correct. Assume the Earth is spherical and isn't rotating. So long as the Earth's density depends only on radius, how that density varies with distance from the center of the Earth does not affect gravity on the surface by one bit. All that matters is the total mass of the Earth. Here are three models for this hypothetical spherical, non-rotating Earth:While that's true, let's go back to the OP's question. ... the approximation of the earth as a sphere whose density depends only on radius is a pretty good one to answer the OP's question.