People say there is weightlessnes

[ShayanJ]

People say there is weightlessness when you get far a little from earth.But we as people who are familiar with phyiscs know that its not true.I've thought about it and found an explanation(prefered to think my own instead of searching for it) based on inertia and I think there is a similar effect when we're in an elevator.But now I'm having troubles with my explanation which takes me in doubt if its right or not.This is my explanation:
imagine we're in an space station which is orbiting earth.The station is experiencing a gravitational force caused by Earth's mass which gives it an acceleration.So our station is accelerated toward earth.We should move with it too but because of inertia,we tend to preserve our last velocity every moment.So at every point of time,our velocity is a bit less than station's velocity and this causes us to feel an imaginary acceleration in the opposite direction of gravitational acceleration and so it looks like that no force is being applied to us which we call weightlessness.
I want to ask you that is this correct?

 

[K^2]

Your explanation is a bit jumbled, so I think you might still be missing a few points, but you're on the right track, at least.

There are a number of ways to explain micro-gravity on an orbital station, but the general idea is this. What you really experience as weight is not so much the gravity but the force applied by the surface that supports you. Gravity acts on all points of your body the same way, and so if nothing was there to prevent them from accelerating, there would be no net strain on your body due to gravity. However, if something prevents your feet from accelerating downwards, e.g. floor, then your feet are preventing the bones in your legs from accelerating downwards, which support the rest of your skeleton, which supports the flesh, and so on. It's the strain on the structure due to the fact that there is a pull of gravity, yet it is prevented from accelerating that is actually experienced as weight.

As soon as you remove the support, that strain goes away. The station accelerates at the same rate as people on the station, so nothing blocks the acceleration of the persons, and that means they experience no weight.A completely different way to look at it is to consider coordinate system rotating with the station. Then you have centrifugal force, the centrifugal force balances the gravity perfectly, and the net force on everything is zero. But this explanation you have to be careful with, as it involves an accelerated frame of reference.

There is also an explanation due to General Relativity which basically says that there is no such thing as force of gravity. But that's a bit more complicated.

 

[ShayanJ]

Let's bring the example to an elevator.Imagine its going down.We feel less strain which means the force that the surface of elevator applies to us is less than the one when its not moving.So we should say that the normal force of elevator's surface is decreased because of its downward motion.I think this is a good explanation becasue when elevator moves upward we feel more strain.
But another question arises.Why the normal force changes due to motions parallel to it?
It takes me back to the explanatin I gave in the first post because normal force depends on weight.

 

[HallsofIvy]

People say there is weightlessness when you get far a little from earth.But we as people who are familiar with phyiscs know that its not true.I've thought about it and found an explanation(prefered to think my own instead of searching for it) based on inertia and I think there is a similar effect when we're in an elevator.But now I'm having troubles with my explanation which takes me in doubt if its right or not.This is my explanation:
imagine we're in an space station which is orbiting earth.The station is experiencing a gravitational force caused by Earth's mass which gives it an acceleration.So our station is accelerated toward earth.We should move with it too but because of inertia,we tend to preserve our last velocity every moment.

No, this is not true. The change in velocity due to a force is instantaneous.

So at every point of time,our velocity is a bit less than station's velocity and this causes us to feel an imaginary acceleration in the opposite direction of gravitational acceleration and so it looks like that no force is being applied to us which we call weightlessness.

If it were true that "our velocity is a bit less than the station's velocity", we would eventually slam into the station wall. Both we and the station start with the same velocity and, since we have the same force applied to us, we always have the same[/b\] velocity as the station- that's we feel "weightless".

I want to ask you that is this correct?

 

[PJC01]

Your explanation is partially correct. Weightlessness is a term used to describe the feeling of being weightless or having no apparent gravitational force acting on our bodies. This can occur in different situations, such as being in orbit around the Earth or being in freefall.

In the case of being in orbit, as you mentioned, the space station is constantly falling towards the Earth due to the gravitational force. However, the station is also moving horizontally at a high speed, which creates a balance between the Earth's gravitational pull and the centrifugal force of the station's motion. This results in a constant state of freefall, where the individuals inside the station experience a feeling of weightlessness.

In the case of being in an elevator, the feeling of weightlessness can also occur when the elevator is accelerating downwards. This creates a state of freefall, where the individuals inside the elevator are falling at the same rate as the elevator. This creates the illusion of weightlessness.

Your explanation is correct in that inertia plays a role in the feeling of weightlessness. In both situations, the individuals are experiencing a state of freefall due to the balance between the gravitational force and their own inertia. However, it is important to note that this does not mean that there is no gravitational force acting on their bodies. Gravity is still present and is the force that is causing the freefall.

In summary, your explanation is a good start in understanding the concept of weightlessness, but it is important to also consider the role of gravity and freefall in this phenomenon. Keep exploring and learning about the principles of physics to deepen your understanding.