Angular Momentum in a Kepler Orbit

AI Thread Summary
In a Kepler orbit scenario, a satellite orbits planet X with a defined angular momentum of 1000 m²/sec. When a second planet, Y, is introduced, the total mass of the system increases, but the distance and velocity of the satellite remain unchanged. As a result, the angular momentum of the system does not increase because neither the momentum nor the radius has changed. The satellite's trajectory will shift from a circular path to an elliptical one due to the gravitational influence of the additional planet. Angular momentum conservation principles can be applied to analyze the new satellite trajectory characteristics.
Rapidrain
Messages
31
Reaction score
0
I got myself here a satellite rotating at a large distance around planet X.

Distance from center of planet X = 100,
mass of the satellite = 1 gram (really small),
mass of planet X = 1.0 kg
velocity of my satellite 10 m/sec
and in this oddball universe the gravitational constant = 10**4

So the satellite-planet X system has an angular momentum of 100 * 10 = 1000 m**2/sec

Now suddenly I place a second planet, planet Y, right next to planet X

mass of planet Y = 1 kg

So at this instant, the central gravitational source is now 2.0 kg but distance is still 100 and velocity of satellite is still 10

My question : has the angular momentum of the system increased?

I'd like to use angular momentum conservation to figure the characteristics of a
satellite / planet / planet trajectory. That's where I'm going with this.
 
Physics news on Phys.org
Hi Rapidrain! :smile:
Rapidrain said:
My question : has the angular momentum of the system increased?

Angular momentum = radius "cross" momentum.

Neither the momentum nor the radius has changed, so the angular momentum is also the same.

The satellite will follow an ellipse instead of its original circle.
 
The rope is tied into the person (the load of 200 pounds) and the rope goes up from the person to a fixed pulley and back down to his hands. He hauls the rope to suspend himself in the air. What is the mechanical advantage of the system? The person will indeed only have to lift half of his body weight (roughly 100 pounds) because he now lessened the load by that same amount. This APPEARS to be a 2:1 because he can hold himself with half the force, but my question is: is that mechanical...
Some physics textbook writer told me that Newton's first law applies only on bodies that feel no interactions at all. He said that if a body is on rest or moves in constant velocity, there is no external force acting on it. But I have heard another form of the law that says the net force acting on a body must be zero. This means there is interactions involved after all. So which one is correct?
Thread 'Beam on an inclined plane'
Hello! I have a question regarding a beam on an inclined plane. I was considering a beam resting on two supports attached to an inclined plane. I was almost sure that the lower support must be more loaded. My imagination about this problem is shown in the picture below. Here is how I wrote the condition of equilibrium forces: $$ \begin{cases} F_{g\parallel}=F_{t1}+F_{t2}, \\ F_{g\perp}=F_{r1}+F_{r2} \end{cases}. $$ On the other hand...
Back
Top