Gravity at space?

Question

If you were for example at the international space station, there was no gravity acting on you there the acceleration downwards will be 0g right?
but what will happen if the station's orbital speed were 0 m/s?
then probelly the station was pulled to earth and will fall downwards
so how does it possible that you feel like no force acting on you and you can still fall to earth if your velocity is 0?

Answer 1

When you are in orbit you are basically 'free falling' around earth. Your tangential velocity is such that although you are still being attracted towards the center of mass of the earth by gravity, you move far enough from the tangential velocity to remain at a constant altitude. So, you are free falling around earth.



Imagine a high speed object passing by the earth. We know that it's trajectory will be curved by the earth as it passes, and then it will continue into space on it's new trajectory. Now imagine a very slow object passing by the earth. It too will follow a curved path, but the path will be highly curved and it will impact the earth. Now imagine an object coming by at just the right critical speed. It will curve around the earth, nether impacting the earth nor escaping back into space. The speed is its orbital speed at a particular distance from the earth. So, it should be clear that just the right tangential velocity at a particular altitude will result in a free fall path around earth.

Answer 2

Like any other orbiting body, the ISS is being accelerated toward Earth by the planet's gravity. So is everything inside it, so the net force of gravity on the station's occupants is zero. If its orbital velocity were suddely reduced to zero the crew would first continue moving in the same direction at the same speed until slammed fatally against the forward bulkhead, but their lifeless bodies would remain essentially weightess until either burned up in the armosphere or torn apart by impact with the ground.

Answer 3

The International space station is experiencing MicroGravity. Gravity is still acting upon the station but your velocity makes it that inertia and the force from gravity is balanced. A stable orbit. If the orbital speed was 0 m/s then the station would fall to the earth from the centre of Gravity (straight down) and would burn up in the process.

Answer 4

But see there is gravity W = mg' = mg(r/R)^2 acting even on the astronauts m. R is the orbital radius and r is the average radius of Earth. g is g.



And that's the centripetal force; to which there is a reaction called the centrifugal force F = m w^2 R where w is the angular speed of the ISS revolution in orbit R.



So there is a net or effective force w = W - F = mg(r/R)^2 - m w^2 R = 0 when they are weightless. And that's why they feel no force.

Answer 5

If you are falling in free space , or in a free falling lift for that matter , you wouldn't feel any force acting on you



And note that whilst falling , you would have a velocity towards the Earth .

Answer 6

the ISS is FALLING at 32ft per sec Square. It is also moving horizontally so fast, that the curve of the Earth drops away under it, as fast as it falls, so it just keeps orbiting around the Earth, theoretically for ever. People inside are free falling too---so they are essentially "weightless" relative to their ship.

Answer 7

You feel no force because the walls and floor of the space station are not pushing on you.