All Questions
Tagged with newtonian-gravityreference-frames
235 questions
4votes
1answer
390views
Orbit of one star relative to another in a binary system
I know from the 1st Kepler Law that: In a binary system, both stars orbit their center-of-mass in an elliptical orbit, with the center-of-mass as one focus but how to prove that the orbit of one ...
2votes
3answers
551views
The problem about relativity in uniform circular motion
Suddenly this question comes to my mind: we make the assumption that in the solar system, the motion of the planets is regarded as a uniform circular motion, and the planets and the sun rely only on ...
- 31
2votes
2answers
141views
Mach's objection towards Newton's bucket experiment
I have a naive question about Mach's objection on Newton's bucket experiment (...read from "In his Philosophiae Naturalis Principia..." paragraph) that was initially intended to serve to ...
- 1,701
0votes
1answer
65views
Why is gravitational force not calculated about center of mass?
For calculation of gravitational force among two extended objects (say two rods kept in a straight line), why do we need to integrate to get the force and not by simply using $\dfrac{GM^2}{d^2}$, with ...
5votes
1answer
71views
Equations of Motion for the $N$-body Problem in the Astrocentric Frame
I’ve been studying Tremaine's Dynamics of Planetary Systems and have hit a roadblock. In Chapter 4, titled 'The $N$-body Problem,' there is a derivation of the $N$-body equations of motion, which can ...
- 1,337
0votes
1answer
92views
Why does the direction of gravity not change in an accelerating elevator?
When an accelerating elevator goes up we take pseudo-force as down and when the elevator goes down we take the pseudo-force as up. This changes the effective gravity but why doesn’t the direction of ...
3votes
5answers
353views
It seems the statement "an object in orbit is in a permanent free fall around Earth" is wrong. Is my understanding correct?
Here is an excerpt from an Wikipedia article on low Earth orbit However, an object in orbit is in a permanent free fall around Earth, because in orbit the gravitational force and the centrifugal ...
- 131
4votes
4answers
809views
What is the relationship between gravitation, centripetal and centrifugal force on the Earth?
I'm trying to analyze a situation wherein a ship is moving across the surface of the earth. I am trying to analyze this situation in a reference frame that is rotating with the earth (NED frame). I am ...
0votes
3answers
111views
Pseudo Orbital motion only due to Coriolis force
Planet, say of mass M and radius R is rotating with some angular velocity ω and a object of mass m (initially on the surface and rotating with the planet) was launched with velocity v vertically ...
- 720
1vote
1answer
74views
Drawing a free-body diagram for a body residing on Lagrange point $L_4$ and $L_5$
I am aware of the fact that Lagrange points $L_4$ and $L_5$ are stable equilibrium points however I cannot understand why they are equilibrium points in the first place. Consider a Earth-Moon system ...
- 263
2votes
3answers
62views
Constant speed (at terminal velocity) and zero $g$
I have read the question What would a person experience in a free-falling elevator in a shaft long enough to reach terminal velocity? here and the answer was that you feel exactly the same if the ...
- 129
2votes
2answers
211views
Centrifugal force has always been a nightmare to me
Suppose I'm in a rotating space station (that is somewhere in free space) and there is no other force. Now how am I supposed to fall to the circumference of the station if nothing pulls me? I will ...
0votes
3answers
310views
Gravitational force and centre of mass
So question goes like "What is the magnitude of gravitation force of the particle due to rod?" In the figure the particle is of mass $m$ and from distance $d$ from end of the rod and the ...
0votes
0answers
91views
Do all bodies in a 3-body system orbit their center of mass with respect to each of the other bodies?
Scenario Consider an empty universe with just the Earth, Moon and the Sun. The Earth and the Sun will rotate about their center of mass, which is inside the Sun. The Earth and the Moon will orbit ...
2votes
2answers
2kviews
Centripetal force on the surface of earth
Initially, I was looking for how centripetal force is produced on the surface of the rotating earth for a mass kept at any latitude. I went through the following threads - Which force provides the ...
