Centrifugal force around planets

[Cemre]

Hello,

When I thought about centrifugal force, gravity came into my mind...

When we tie a rope around a ball and rotate it in the air, rope gets some tension ( small displacement between atoms of rope ) and we feel this as centrifugal force. This force occurs because we apply an electromagnetic force to the electrons of the atoms around the ball by the electrons of the rope. but we don't apply the same force to inner atoms of the ball so inner atoms tend to go slightly outwards from the center of the ball and cause a small displacement withing the ball. it is that displacement that we feel as tension and centrifugal force. ( correct me if I am wrong... )

But things differ with gravity. gravity goes and reaches to ALL the atoms of a planet when it is in orbit. and gives every atom the same acceleration ( tidal effects ignored ). orbiting a planet is like a continuous free fall. if every atom gets the same acceleration, distances between the atoms will not change and therefore we won't be able to measure any tension on the planet.

So my question is; do we really feel an outwards centrifugal force when we are in orbit?

 

[Ich]

it is that displacement that we feel as tension and centrifugal force.

That's centripetal force. It acts through the rope, and is different from gravity. It's simply a force.
Centrifugal force acts on every single bit of matter, exactly like gravity. Both, gravitational force and centrifugal force, are fictional forces. They vanish if you calculate things in a local inertial frame, where F=ma.

 

[Entropia]

Thank you for your explanation on centrifugal force and gravity. You are correct in your understanding that centrifugal force is caused by the tension in the rope due to the difference in forces applied to the atoms on the outer and inner sides of the ball. This results in a small displacement within the ball, which we feel as tension and centrifugal force.

However, you are also correct in noting that things differ with gravity. In the case of orbiting a planet, the force of gravity is acting on all the atoms of the planet, causing them to continuously fall towards the center of the planet. This results in a balanced force throughout the planet, without any noticeable tension or centrifugal force.

So to answer your question, in orbit, we do not feel an outwards centrifugal force as the force of gravity is acting on all the atoms of the planet and keeping them in a continuous free fall. This is why astronauts in orbit experience weightlessness, as they are essentially falling towards the Earth at the same rate as the space station they are in.

I hope this helps clarify any confusion and thank you for your question.