How high do you have to go to reach weightlessness

Question

How high do you have to go to reach weightlessness

Answer 1

Jump off a building - you will be weightless on the way down.  That is exactly what the astronauts are doing - falling.

Here is how it works.  Imagine you shoot an artillery shell.  It goes a ways and finally hits the ground.  Put a bigger charge in the gun and it will go farther.  If you fire it fast enough (and high enough so there is no air friction to slow it down) it will start to fall but the curvature of the Earth will fall away too.  

With just the right velocity your shell will orbit the Earth which is just what the astronauts are doing.  They are both falling and moving forward enough so the ground below them falls away at the same rate they fall toward it.

Answer 2

not that much. it depends on how long you want to have this effect take part.

to have it just for a fraction of a second you simply need to make a jump.

its also not that much a question of height, its more a question about height and velocity.

to have a constant feeling of weighlessness you need to travel near the speed of earth-escape-velocity, which is somewhere around 28.000 km/hour, which is just possible in the higher athmosphere to avoid your vehicle heating up from friction caused by air-molecules

let's agree on 300km above ground and a speed of 28.000 km/h, for a true microgravity experience, for hours, if not days

let's agree on 100km height and  0 km/h like space-ship-one for 90 seconds of freefall-weightlessness, just enough to see a few smarties flying around in your cabin

Answer 3

The other answers give you the details, but put simply, there's more to weightlessness then that.

Answer 4

The effects of gravity decrease over distance according to the inverse square law so no matter how far from anything else an entity is, gravity still affects it. However, if it is accelerated towards the source of gravity at the right speed (for example, freefall in a vacuum), it becomes weightless.

Answer 5

Misconception.

Answer 6

In literal meaning, Outside the earth's gravity(say atmosphere) we experience weightlessness.