#Why am I spinning?

To be precise, lets assume you are an astronaut that has returned to earth after being in a non-geosynchronous orbit. After landing you are now at rest with respect to the surface of the earth in your general area.

The reason you are spinning with the earth is quite simple. Gravity is pushing you against the surface of the earth. There is friction between you an the earth as a result of the pressure between you and the surface. That pressure is caused by your weight i.e. gravity. That friction causes your body to move with the surface in the same way that a moving sidewalk moves you when you are standing on it.

#But if there is no centripetal force then why am I spinning?

Centripetal force does not initiate your motion. The speed component of your velocity is not a result of centripetal force. Centripetal force changes the direction component of your velocity. In other words centripetal force changes the direction of your movement such that you follow the curved path around the center of the earth. Another way think about it is: the direction of your velocity is always orthogonal to the direction of the centripetal force and therefore the centripetal force doesn't contribute to the speed component of your velocity.

For reference, here's a simple diagram of centripetal motion and how the force and velocity relate (source):

Centripetal force, in this example, is always directed towards the center of the earth which, not coincidentally, is the same direction that gravity points. The reason is that in this case the centripetal force is caused by gravity. If gravity were to somehow stop pulling you towards the center of the earth your body would continue in a straight line tangent to the earth. At first you would seem to float up but as you continued on this path, you would leave vicinity of the earth entirely.

Why am I spinning?

To be precise, lets assume you are an astronaut that has returned to earth after being in a non-geosynchronous orbit. After landing you are now at rest with respect to the surface of the earth in your general area.

The reason you are spinning with the earth is quite simple. Gravity is pushing you against the surface of the earth. There is friction between you an the earth as a result of the pressure between you and the surface. That pressure is caused by your weight i.e. gravity. That friction causes your body to move with the surface in the same way that a moving sidewalk moves you when you are standing on it.

But if there is no centripetal force then why am I spinning?

Centripetal force does not initiate your motion. The speed component of your velocity is not a result of centripetal force. Centripetal force changes the direction component of your velocity. In other words centripetal force changes the direction of your movement such that you follow the curved path around the center of the earth. Another way think about it is: the direction of your velocity is always orthogonal to the direction of the centripetal force and therefore the centripetal force doesn't contribute to the speed component of your velocity.

For reference, here's a simple diagram of centripetal motion and how the force and velocity relate (source):

Centripetal force, in this example, is always directed towards the center of the earth which, not coincidentally, is the same direction that gravity points. The reason is that in this case the centripetal force is caused by gravity. If gravity were to somehow stop pulling you towards the center of the earth your body would continue in a straight line tangent to the earth. At first you would seem to float up but as you continued on this path, you would leave vicinity of the earth entirely.

#Why am I spinning?

To be precise, lets assume you are an astronaut that has returned to earth after being in a non-geosynchronous orbit. After landing you are now at rest with respect to the surface of the earth in your general area.

The reason you are spinning with the earth is quite simple. Gravity is pushing you against the surface of the earth. There is friction between you an the earth as a result of the pressure between you and the surface. That pressure is caused by your weight i.e. gravity. That friction causes your body to move with the surface in the same way that a moving sidewalk moves you when you are standing on it.

#But if there is no centripetal force then why am I spinning?

Centripetal force does not cause you to move. By that I mean the speed component of your velocity is not a result of centripetal force. Centripetal force changes the direction component of your velocity. In other words centripetal force changes the direction of your movement such that you follow the curved path around the center of the earth. Another way think about it is: the direction of your velocity is always orthogonal to the direction of the centripetal force and therefore the centripetal force doesn't contribute to the speed component of your velocity.

For reference, here's a simple diagram of centripetal motion and how the force and velocity relate (source):

Centripetal force, in this example, is always directed towards the center of the earth which, not coincidentally, is the same direction that gravity points. The reason is that in this case the centripetal force is caused by gravity. If gravity were to somehow stop pulling you towards the center of the earth your body would continue in a straight line tangent to the earth. At first you would seem to float up but as you continued on this path, you would leave vicinity of the earth entirely.

#Why am I spinning?

To be precise, lets assume you are an astronaut that has returned to earth after being in a non-geosynchronous orbit. After landing you are now at rest with respect to the surface of the earth in your general area.

The reason you are spinning with the earth is quite simple. Gravity is pushing you against the surface of the earth. There is friction between you an the earth as a result of the pressure between you and the surface. That pressure is caused by your weight i.e. gravity. That friction causes your body to move with the surface in the same way that a moving sidewalk moves you when you are standing on it.

#But if there is no centripetal force then why am I spinning?

Centripetal force does not initiate your motion. The speed component of your velocity is not a result of centripetal force. Centripetal force changes the direction component of your velocity. In other words centripetal force changes the direction of your movement such that you follow the curved path around the center of the earth. Another way think about it is: the direction of your velocity is always orthogonal to the direction of the centripetal force and therefore the centripetal force doesn't contribute to the speed component of your velocity.

For reference, here's a simple diagram of centripetal motion and how the force and velocity relate (source):

Centripetal force, in this example, is always directed towards the center of the earth which, not coincidentally, is the same direction that gravity points. The reason is that in this case the centripetal force is caused by gravity. If gravity were to somehow stop pulling you towards the center of the earth your body would continue in a straight line tangent to the earth. At first you would seem to float up but as you continued on this path, you would leave vicinity of the earth entirely.

#Why am I spinning?

To be precise, lets assume you are an astronaut that has returned to earth after being in a non-geosynchronous orbit. After landing you are now at rest with respect to the surface of the earth in your general area.

The reason you are spinning with the earth is quite simple. Gravity is pushing you against the surface of the earth. There is friction between you an the earth as a result of the pressure between you and the surface. That pressure is caused by your weight i.e. gravity. That friction causes your body to move with the surface in the same way that a moving sidewalk moves you when you are standing on it.

#But if there is no centripetal force then why am I spinning?

Centripetal force does not cause you to move. By that I mean the speed component of your velocity is not a result of centripetal force. Centripetal force changes the direction component of your velocity. In other words centripetal force changes the direction of your movement such that you follow the curved path around the center of the earth. Another way think about it is: the direction of your velocity is always orthogonal to the direction of the centripetal force and therefore the centripetal force doesn't contribute to the speed component of your velocity.

Centripetal force, in this example, is always directed towards the center of the earth which, not coincidentally, is the same direction that gravity points. The reason is that in this case the centripetal force is caused by gravity. If gravity were to somehow stop pulling you towards the center of the earth your body would continue in a straight line tangent to the earth. At first you would seem to float up but as you continued on this path, you would leave vicinity of the earth entirely.

#Why am I spinning?

To be precise, lets assume you are an astronaut that has returned to earth after being in a non-geosynchronous orbit. After landing you are now at rest with respect to the surface of the earth in your general area.

The reason you are spinning with the earth is quite simple. Gravity is pushing you against the surface of the earth. There is friction between you an the earth as a result of the pressure between you and the surface. That pressure is caused by your weight i.e. gravity. That friction causes your body to move with the surface in the same way that a moving sidewalk moves you when you are standing on it.

#But if there is no centripetal force then why am I spinning?

Centripetal force does not cause you to move. By that I mean the speed component of your velocity is not a result of centripetal force. Centripetal force changes the direction component of your velocity. In other words centripetal force changes the direction of your movement such that you follow the curved path around the center of the earth. Another way think about it is: the direction of your velocity is always orthogonal to the direction of the centripetal force and therefore the centripetal force doesn't contribute to the speed component of your velocity.

For reference, here's a simple diagram of centripetal motion and how the force and velocity relate (source):

Centripetal force, in this example, is always directed towards the center of the earth which, not coincidentally, is the same direction that gravity points. The reason is that in this case the centripetal force is caused by gravity. If gravity were to somehow stop pulling you towards the center of the earth your body would continue in a straight line tangent to the earth. At first you would seem to float up but as you continued on this path, you would leave vicinity of the earth entirely.