Earth's Rotation: Centripetal Acceleration Source

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Discussion Overview

The discussion revolves around the centripetal acceleration associated with Earth's rotation about its axis. Participants explore the forces involved in this acceleration, considering both theoretical and conceptual aspects of rotational motion.

Discussion Character

  • Exploratory, Technical explanation, Conceptual clarification, Debate/contested

Main Points Raised

  • One participant questions the source of the centripetal acceleration necessary for Earth's rotation, seeking clarification on the forces involved.
  • Another participant suggests that gravity and contact forces provide the necessary radial force, directing it towards the axis of rotation.
  • A different viewpoint posits that, when considering Earth as a solid body, no external force is needed for its rotation due to the conservation of angular momentum, while gravity acts as a centripetal force for its complex structure.
  • One participant expresses skepticism about the relationship between centripetal acceleration and Earth's rotational motion, arguing that centripetal acceleration does not cause rotation and questions what torque is responsible for the Earth's rotation.
  • A repeated question about the source of centripetal acceleration highlights a potential misunderstanding or need for further discussion on the topic.

Areas of Agreement / Disagreement

Participants express differing views on the nature of the forces involved in Earth's rotation and the role of centripetal acceleration, indicating that multiple competing perspectives remain without consensus.

Contextual Notes

Some claims depend on specific interpretations of Earth's structure (solid vs. complex) and the definitions of forces involved, which may not be fully resolved in the discussion.

skepticsm
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I have a question about the centripetal acceleration required for Earth's rotation about its axis. There obviously must be a force causing this acceleration, but I can't seem to figure what the source of this force is. Anyone happen to know the answer?
 
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For any piece of the Earth not on the axis of rotation there will be a net centripetal force. Gravity and contact forces (from surrounding material) provide the radial force, the net of which is towards the axis of rotation.
 
Hi,
Regarding the Earth as simple solid body, no outer force is required for spinning of the Earth by the conservation law of angular momentum.
Regarding the Earth as complex of parts, part of gravity to the center of Earth works as centripetal force to keep them not dispersed.
Regards.
 
Skepticsm, centripetal acceleration is in the radial direction, but the earth’s rotational motion is in the tangential direction. As such, centripetal acceleration does not cause the earth’s rotation--I am taking the Earth's radius to be a constant here. Did you mean to ask: what torque acts upon the Earth to cause its rotation?
 
Last edited:
skepticsm said:
I have a question about the centripetal acceleration required for Earth's rotation about its axis. There obviously must be a force causing this acceleration, but I can't seem to figure what the source of this force is. Anyone happen to know the answer?
Rain.
 

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