Recent content by Bob Jones

Oh... Wait. This is the old version of this. I understand how it works now. Could someone tell me how geometrically or algebraically you can derive b2 = ra * rb?

From a wiki's vis-viva equation page, it is given that the specific angular momentum h is also equal to the following: h = wr^2 = ab * n How can ab * n be derived to be equal to the angular momentum using elliptical orbit energy/momentum/other equations without having to use calculus or...

Thanks for the help! :)

That's a good point. Also, I'll have to consider what values I am considering when I am thinking of the error. All right. Let's say the distance between the planet and satellite is R. If I wanted the planet to move a maximum of R/1000 from the position where it would be considered 'static' from...

Basically, I wish to know what relative ratios of distances and/or masses can we assume that the effect of the gravitational pull of the satellite on the planet is small enough such that we can assume the planet is fixed with little error.

Since we are on the topic of Kepler's laws of planetary motion, I have another question. One of the assumptions made when using Kepler's laws is that the orbited mass is much greater than the mass orbiting it, which is why it can be assumed to be 'fixed' without much error. My question is what...

While that is probably what was meant or at least what is actually correct, the source of the image says tangential.

Yes, it seems I did not use the correct terminology, and I had a misunderstanding based on what I thought was correct, especially after seeing the last comment to the question here.

As said above, I meant perpendicular to the radius. You seem to be correct in that I was incorrectly labeling what I was looking for as 'tangential velocity,' so I apologize for that. Thanks for helping me improve my understanding.

From my understanding, the total velocity is pointing slightly away from the ellipse at points in which it is not tangent. This image displays what I mean.

By total velocity, I meant the total relative velocity of the satellite. As for tangential velocity, I meant the component of the total relative velocity that is perpendicular to the radius. Also, is there a way to end a topic? I found what I was looking for.

Well, I've been an idiot. All I needed to do was multiply the angular velocity by the radius to get the tangential velocity. And I can get total velocity by v = sqrt(GM * (2/r - 1/a))

Well, they are variables. You can change them in the code. I just meant that I was going to add the ability for the user to change it in the UI.

It seems I was not being very clear with my intentions. The simulation functions well. The part where I mentioned that I was in progress of building the simulation was referring to how I was going to allow the user to specify the radii and mass of the planet being orbited instead of using...

Well, both... What I meant by the first statement is that it shows the position the satellite it would be with the correct period by adding the angular velocity multiplied by the time it takes the program to loop to that part of the code to the angle. The radius is dependent on the angle. With...