Earth's Rotation: Centripetal Acceleration Source

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SUMMARY

The centripetal acceleration necessary for Earth's rotation is primarily provided by gravitational forces and contact forces from surrounding materials, directing towards the axis of rotation. The conservation of angular momentum explains that no external force is needed for the Earth to maintain its spin as a solid body. However, when considering the Earth as a complex system, gravity acts as a centripetal force preventing dispersion of its components. The discussion clarifies that centripetal acceleration does not initiate Earth's rotation; rather, it is the result of the existing rotational motion.

PREREQUISITES
  • Understanding of centripetal acceleration and its role in rotational dynamics.
  • Knowledge of gravitational forces and their effects on celestial bodies.
  • Familiarity with the conservation of angular momentum principles.
  • Basic concepts of torque and its influence on rotational motion.
NEXT STEPS
  • Research the principles of gravitational forces in celestial mechanics.
  • Study the conservation of angular momentum in rotating systems.
  • Explore the relationship between torque and rotational motion in physics.
  • Investigate the effects of centripetal acceleration on objects in circular motion.
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Students of physics, astrophysicists, and anyone interested in understanding the dynamics of Earth's rotation and the forces involved in celestial mechanics.

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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