Does the Center of Mass Affect Gravity?

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Discussion Overview

The discussion revolves around the relationship between the center of mass of objects and the gravitational pull experienced at that point. Participants explore whether all objects exhibit zero gravitational pull at their center of mass and consider specific examples to illustrate their points.

Discussion Character

  • Exploratory, Conceptual clarification, Debate/contested

Main Points Raised

  • One participant suggests that if you are at the center of a sphere, you would feel no gravitational pull in any direction, leading to the question of whether all objects have zero gravitational pull at their center of mass.
  • Another participant agrees that a body does not necessarily have zero gravitational field at its center of mass, using the example of a lead ball connected to a wood ball to illustrate that the gravitational pull can vary depending on the mass distribution.
  • A later reply mentions that a similar effect occurs with the Sun and the Earth, implying that the gravitational dynamics can be complex and depend on the arrangement of masses.

Areas of Agreement / Disagreement

Participants do not reach a consensus on whether all objects have zero gravitational pull at their center of mass, as different examples and interpretations are presented.

Contextual Notes

The discussion includes assumptions about symmetrical arrangements and the specific configurations of masses, which may affect the gravitational pull experienced at the center of mass.

cragar
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I was thinking that objects like a sphere have a center of mass in the middle of the sphere and also if you were in the middle of the sphere you would feel no gravitational pull in any direction. So then I was wondering if all objects had a zero gravitational pull at their center of mass. But then I thought of a large lead ball connected to a smaller wood ball with a thin rod between them, and the center of mass would be closer to the larger lead ball, because that's where it would balance. But it seems that the pull would be zero closer to smaller wood ball.
Am I thinking about this correctly.
 
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Yes. A body need not have zero gravitational field due to its own mass at its center of mass, as your example illustrates nicely. For some symmetrical arrangements, it will work out that way of course.
 
ok thanks for your answer .
 
The same effect happens with the Sun and the Earth.
 

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