Does Earth's Rotation Affect Gravity?

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SUMMARY

The discussion clarifies that Earth's rotation does not determine the strength of gravity; rather, gravity is solely dependent on Earth's mass. If Earth were to stop spinning, individuals would not float into space due to gravity being approximately 30 times stronger than the centripetal force generated by Earth's rotation. The misconception that spinning creates a force that "holds people down" is addressed, emphasizing that centripetal force is necessary for circular motion. Thus, even without rotation, gravity would still keep individuals grounded on Earth.

PREREQUISITES
  • Understanding of basic physics concepts, particularly gravity and centripetal force.
  • Familiarity with Newton's laws of motion.
  • Knowledge of Earth's mass and its gravitational effects.
  • Basic comprehension of rotational dynamics.
NEXT STEPS
  • Research the relationship between mass and gravitational force using Newton's law of universal gravitation.
  • Explore the concept of centripetal force and its role in circular motion.
  • Study the effects of Earth's rotation on weight and perceived gravity.
  • Investigate the implications of a non-rotating Earth on climate and environmental conditions.
USEFUL FOR

Students of physics, educators explaining gravitational concepts, and anyone interested in the effects of Earth's rotation on gravity and motion.

Clubbes
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Homework Statement


I do not know if this is the right forum to be asking this, but it is the best i have found.

A classmate of mine came with the statement that if the Earth stopped spinning we would all float off to space because the Earth's mass is to small to able to hold everyone down.
I am reluctant to believe this as my limited understanding of physics says that mass is the decider of the strength of gravity, not that it need to rotate aswell.

The question is, if the Earth and everyone on it lost its momentum. would we still be on earth? or would we float out to space.
This question is not taking into consideration that we would either freeze or burn since the sun would cook one side and the other side would freeze. (please correct me on this if i am wrong.)

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The Attempt at a Solution

 
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I suspect someone has misunderstood a claim and constructed their own spurious explanation.
The original may have been "if the Earth suddenly stopped spinning then we would all fly off nto space because of our own momentum".
Even then, it is wrong. It would certainly be unpleasant, but Earth's gravity is much stronger (about 30 times as strong) as the centripetal force required to keep us on terra firma.
 
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Clubbes said:
A classmate of mine came with the statement that if the Earth stopped spinning we would all float off to space because the Earth's mass is to small to able to hold everyone down.

They are very confused. Spinning doesn't produce a force that "holds people down". If it did then mud wouldn't fly off a car/bike wheel. On the contrary.. spinning requires a force (centripetal force) to make things move in a circle and stop mud or people flying off. So someone on a spinning planet appears to weigh slightly less than someone on a non spinning planet.

If your friend was correct, what would happen to someone when they reach the north pole?
 
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