All Questions
11
questions
1
vote
1
answer
631
views
What is the equation describing earth's orbit around the sun in 3 dimensional space?
I'm trying to draw a 2d ellipse in 3d space, which describes earth's orbit around the sun. such as image of a 2d ellipse in 3d space or the same image but different perspective. I'd like to be able to ...
- 11
-1
votes
1
answer
39
views
Equation for area of ellipse given length of major axis and position of focus along the major axis? [closed]
I'm solving a physics question where the nearest and furthest distance of a satellite from Earth are given, along with the satellite's speed at the nearest point, and it asks to find the period of the ...
- 369
1
vote
2
answers
450
views
Intensity of parabolic reflector as a function of the radius.
I'm trying to make sense of the intensity of light leaving a parabolic reflector, given that the light is a point source at the focus. (In the diagram below, this might be the intensity of light at $...
- 5,072
1
vote
1
answer
126
views
Fixing an orbit in space using r and v (Keplerian orbits)
I'm wondering what would be a good geometric method to compute orbital elements that fix the orbit in space, given that one is given the position vector $\vec{r}$ and the velocity vector $\vec{v}$ for ...
- 135
0
votes
1
answer
406
views
Centripetal acceleration in Kepler orbit in cartesian coordinate
I have some difficult in deriving the formula for centripetal acceleration of a planet in solar system moving in elliptical orbit with constant areal velocity $\dot S$.
The book report the formula in ...
- 395
0
votes
1
answer
130
views
A question about math behind circle and ellipse made by a line of neutrino (Cherenkov Cone)
A line of Neutrino is moving on the shape. When it moves through something like water, It makes a cone (Cherenkov radiation) which as you see, the line making the cone has angle $\phi$ with the line ...
- 749
1
vote
1
answer
1k
views
Geometric proof re: parabola focus and potential calculus connection
The image above is a proof that light traveling with an orientation perpendicular to the directrix into a parabola will be reflected to the focus of the parabola. (In the diagram, the purple dotted ...
- 464
5
votes
8
answers
16k
views
Using polar coordinates to find the area of an ellipse
Considering an ellipse with the $x$ radius equal to $a$ and the $y$ radius equal to b$:$
I figured that some kind of parameterization might be:
$x=a\cos\theta$
$y=b\sin\theta$
and then polar $r^2$...
- 51
3
votes
2
answers
1k
views
How do I deal with reflections inside an ellipse?
Suppose I have an ellipse with foci $F_1$ and $F_2$. How do I show that any ray of light which intersects the segment connecting the foci will have subsequent reflections that always are tangent to ...
- 571
2
votes
1
answer
2k
views
Throwing a Projectile in 2D space
Normally I am strong at maths, but here I have a Math question that after spending 5 pages, I just can't figure it out. Here goes:
A person is playing a game that requires throwing an object onto a ...
- 125
2
votes
2
answers
135
views
Ball from platform with specific vertex
On earth in a vacuum. You throw a platon from a platform height
$h$ and want it to land at point $d$ distant. Note, h is absolutely fixed and d is absolutely fixed. It "must land" at point d, no ...
- 1,345