All Questions
6
questions
0
votes
1
answer
546
views
Gravitational field strength between equipotential lines
Is the gravitational field strength between two equipotential lines the same at all distances? For example, in the image, does point P experience the same gravitational field strength as a point ...
- 15
0
votes
1
answer
80
views
Internal and external gravitational potentials $V(r)$ of a spherical object of matter of constant total mass $M$, and variable radius $R$
$\newcommand{\oiint}{\iint\limits_{\partial V}\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\;\;\;\subset\!\supset }$
Imagine a ball of dust of total mass $M$ and radius $R$. The total mass of the ball remains ...
0
votes
2
answers
202
views
Is there a special name for this vector field?
The gravitational field of a point mass can be shown to be solenoidal (i.e. its divergence is zero) at all points except where the point mass actually is. This implies that there exists a vector field ...
- 245
0
votes
1
answer
87
views
Use divergence theorem to compute acceleration of a sphere [closed]
Suppose we have $\vec{F}$ being the force on a proof mass $m$ in the field of a mass $M$ with mass density $\rho(\vec{r})$ given by $\vec{F}(\vec{r})= m\vec{g}(\vec{r})$ and $\vec{g}(\vec{r}) = \nabla ...
- 103
-2
votes
1
answer
75
views
If $\vec{F}=-\nabla V$ and $V ∝ 1/r^2$, then shouldn't objects fly up instead of fall down?
If the apple moves from the higher potential to lower potential $(\vec{F}=-\nabla V)$ and the closer the distance the higher potential $(V ∝ 1/r^2)$, then shouldn't the apple fly up instead of fall ...
- 929
4
votes
3
answers
2k
views
Is the curl of the gravitational field required to fully describe Newtonian gravity?
We are familiar with Newton's law of gravitation:
$$\textbf{F} = \frac{-GMm}{r^2} \hat{\textbf{r}},\tag{1}$$
which leads to a gravitational field strength relation:
$$\textbf{g} = \frac{-GM}{r^2} \...
- 175