Understanding Orbital Momentum: The Mysterious Formulation Explained

In summary, the conversation discusses a question about a formulation of orbital momentum, which is presented as p = miv/(2πl) = const. The connection between this formulation and the well-known p = mv is unclear, and the conversation continues to seek clarification on the concept.
  • #1
DesertFox
Hello everybody!
I'm layman in physics, but recently I have very strong interest. Now I am struggling to obtain some knowledge all by myself. That's so complex, probably impossible for me... that's why i decided to sign up in the forum and I hope to get help from people who are versed and educated in physics.

Here is the first question which I hope to get answer...
I know about the notorious formulation: p = m x v
p - momentum;
m - mass;
v - velocity.

Two weeks ago, I read a text about "free moving (circulation) in gravitational orbit". In the text they talk about orbital momentum. The formulation of orbital momentum was presented as: p = miv/(2πl) = const
p - orbital momentum;
m - mass;
iv - orbital velocity, also: velocity of circulation (it was represented as a kind of imaginary velocity; i - imaginary unit ?)
2πl - orbital length (circumference).

I searched in the physics textbooks, which I have at home... I searched in google... but i can't find information (and explanation) about this formulation.
"p = m x v" is derived from "p = miv/(2πl)"? Or "p = miv/(2πl)" is derived from "p = m x v"?
I will be very thankful for every comment about this mysterious formulation ( p = miv/(2πl) )...

Have a nice day everybody! :approve::approve::approve:

P.S. English is not my native language, but I hope I managed to ask my questions clearly enough..
 
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  • #2
Hello Fox, :welcome:

Your i has nothing to do with imaginary numbers. Check out angular momentum and perhaps it becomes clearer.

Your notation is understandable but leads to confusion: physicists use x for vector products and bold face for vectors (or an arrow above a vector quantity).
So translational momentum vector ##\vec p## is defined as ##\vec p \equiv m\vec v ##
And angular momentum ##\vec L \equiv \vec r \times \vec v## as you find in Wikipedia.

Talking about orbital momentum is confusing. Could you refer us to the precise wording or post a piece of context ?
DesertFox said:
The formulation of orbital momentum was presented as: p = miv/(2πl) = const
looks weird dimensionally: mass/time ?
 
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Likes DesertFox
  • #3
The original text is written in bulgarian language, so it is difficult to translate it literally.
I will try one more time to represent the question and i will make some corrections in my questions.

Here it is in short:
He (the author) talks about a free movement (circulation) in gravitational orbit and he describes the momentum like this: p = miv/(2πl) = const
p - momentum;
iv - orbital velocity (velocity of circulation);
2πl - orbital length (perimeter of circumference).

After that, he says:
when we have 2πl= i (imaginary number), we get: p = mv

I can't grasp his idea. The final formulation (p = mv) is OK, it is notorious.But his primary formulation ( p = miv/(2πl) = const )... I can't understand it...

I hope I made my question more clear and I look for help.o_O
 
  • #4
Can't say it helps me understand better. ##2\pi l = i ## simply can't be meaningful to me either.

Is there a connection with the Kepler laws in the bul.. (sorry about the pun) story ?
 

Related to Understanding Orbital Momentum: The Mysterious Formulation Explained

1. What is orbital momentum?

Orbital momentum is a measure of the rotational motion of an object, such as a planet or satellite, as it orbits around another object. It is a vector quantity that takes into account the object's mass, velocity, and distance from the center of rotation.

2. Why is orbital momentum important?

Understanding orbital momentum is crucial for predicting and analyzing the motion of objects in space. It helps scientists calculate trajectories, determine the stability of orbits, and make predictions about the behavior of celestial bodies.

3. How is orbital momentum calculated?

The formula for orbital momentum is L = mvr, where L is the orbital momentum, m is the mass of the object, v is its velocity, and r is the distance from the center of rotation. This formula can be applied to both circular and elliptical orbits.

4. What factors affect orbital momentum?

The two main factors that affect orbital momentum are mass and velocity. A change in either of these variables will result in a change in the orbital momentum. Additionally, the distance from the center of rotation also plays a role, with a larger distance resulting in a greater orbital momentum.

5. How is orbital momentum related to angular momentum?

Orbital momentum and angular momentum are closely related, with angular momentum being a specific type of orbital momentum that takes into account the object's rotational motion. Angular momentum is calculated by multiplying the orbital momentum by the object's radius, making it a measure of the object's spin around its own axis.

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