g=gravitational acceleration
2006-10-24 10:22:30 · 8 answers · asked by Anonymous in Science & Mathematics ➔ Astronomy & Space
Sure. At least anywhere outside the event horizon, the standard formula for gravity still applies... it's just a large mass.
g = G Mb r^-2
where G is the universal Gravitational constant, Mb is the mass of the black hole, r is the distance from the center of the black hole.
Aloha
2006-10-24 10:26:36 · answer #1 · answered by Anonymous · 4⤊ 1⤋
haha, good question!
wel, as for now, all these formulae these pals are suggesting apply to only matter whose mass is known. As what Einstein had said, black hole is to be treated altogether differently, nothing to be related with at all.
I'll begin with the What question, what is a black hole. Its mass tending to infinity in most condensed form in less than volume of a nucleus of an atom. Naturally when such mass is condensed into so small volume, we cant really calculate the exact gravitational force since mass can not be calculated.
One more interesting aspect of its existance, the gravitational acceleration, which actually sucks even time, oh yes, time. Since gravitational force is such that it curves the light travelling in the straight line and sucks all into it and let it not escape. Just when the light is about to be sucked, it accelerates. yes, the most confusing part of the general theory of relativity, is how can light accelerate even more when it is to be considered the most univeral constant by Einstein himself.
Hence it means, that when light accelerates into the black hole, its in speed more than the speed of light we understand, i.e, 3 lacKMperSec. This is not possible!!! because for this, one has to take negative energy and mass, not infinite.
So your question remains behind by miles, because the black hole must not even exist in terms of Physics. But it does, we can see it (i mean, can not see, but assume) which means the formulae we are using are wrong. So precisely, your question remains unanswerable for lack of correct theories and formulaes.
In other words, NO, there is no formula for measuring 'g' of black holes.
2006-10-28 17:19:21 · answer #2 · answered by swadesipal 2 · 0⤊ 0⤋
For any body,
g = G M / r^2
Where G is the universal gravitational constant, M is the mass of the body in question, and r is the radius of the body in question.
Obviously, since a black hole has no surface, its r is zero and g is therefore infinite. Therefore, it is common to speak of a Black Hole's "event horizon", which is the radius r at which the escape velocity is the speed of light.
2006-10-24 17:28:42 · answer #3 · answered by Keith P 7 · 2⤊ 1⤋
It is my understanding that the equation g=Gm/r^2 is not adequate for black holes and you need to use general relativity to solve for g. An equation does exist however. I just don't know it.
Also due to time and space dilation the idea of acceleration gets slightly more complicated.
2006-10-24 19:59:52 · answer #4 · answered by sparrowhawk 4 · 0⤊ 0⤋
just use the same formula that you would for any other object. there's nothing mysterious about a black hole other then that it's really massive and really small. if you're far enough away you could orbit a black hole just like you'd orbit the sun or the earth.
2006-10-24 17:26:41 · answer #5 · answered by Kyrix 6 · 2⤊ 1⤋
see first of all tell me what is the mass of black hole.and then its size .first of all it is not proved till now that black hole really exists.if it exists its mass should be known which is not.u cannot apply gravitational laws as its mass is not defined!!!
2006-10-27 05:07:43 · answer #6 · answered by shaurya_coolman 1 · 0⤊ 0⤋
black holes have infinite g. it is not governed by the normal physics
2006-10-25 00:21:05 · answer #7 · answered by srikanta 2 · 0⤊ 0⤋
no
2006-10-28 08:29:41 · answer #8 · answered by HARSH V 1 · 0⤊ 0⤋