falling in a vacuum container

How does science work? And what's all this about quantum mechanics?

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duszek
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falling in a vacuum container

Post by duszek » Wed Mar 01, 2017 7:17 pm

Most people have seen the impressive experiment with a heavy object and a feather falling to the ground at exactly the same speed.

What would happen if we attached a little parachute to the heavy object ?

Metazoan
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Re: falling in a vacuum container

Post by Metazoan » Wed Mar 01, 2017 8:27 pm

duszek wrote:Most people have seen the impressive experiment with a heavy object and a feather falling to the ground at exactly the same speed.

What would happen if we attached a little parachute to the heavy object ?
Hi duszek,

We would give it a false sense of security.

Until it pulled the rip-cord...

M.

duszek
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Re: falling in a vacuum container

Post by duszek » Sun Mar 05, 2017 9:17 am

Thank you M. :lol:

How would it look like for someone watching from outside ?
Probably the parachute would be dragged behind the heavy object as if it were full of holes.

This could be used in a suspense novel.

A character is watching and thinking: the Martians are going to put me into a funny container in which a parachute without holes behaves as if it had lots of them. Funny.
They try to put me under pressure by letting me watch this.
Can´t they think of anything better for a torture instrument ?

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Harbal
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Re: falling in a vacuum container

Post by Harbal » Sun Mar 05, 2017 12:32 pm

Metazoan wrote:
duszek wrote:
What would happen if we attached a little parachute to the heavy object ?

We would give it a false sense of security.

M.
10/10 :lol:

Metazoan
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Re: falling in a vacuum container

Post by Metazoan » Sun Mar 05, 2017 2:13 pm

Hi duszek,
duszek wrote:How would it look like for someone watching from outside ?
The heavy object would pull the rip-cord and very little would happen. The drogue would just sit there.

A short while later the heavy object would appear to open its mouth.

But in a vacuum, no one can hear it scream.
duszek wrote:Probably the parachute would be dragged behind the heavy object as if it were full of holes.
What would drag the 'chute? No air, no drag.

It wouldn't matter if the 'chute had no holes or was made of concrete. Everything in the same gravitational field accelerates at the same rate unless there is an unequal opposing force. Air provides this through drag. Vaccum = no air = no drag.

If it was a smart heavy object it could throw the 'chute downwards as hard as it could and that may delay it long enough to have a softer landing on the feather.

Tough on the feather though.
duszek wrote:This could be used in a suspense novel.

A character is watching and thinking: the Martians are going to put me into a funny container in which a parachute without holes behaves as if it had lots of them. Funny.
They try to put me under pressure by letting me watch this.
Can´t they think of anything better for a torture instrument ?
Let's not start you know who off again.

M.

Metazoan
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Re: falling in a vacuum container

Post by Metazoan » Sun Mar 05, 2017 2:16 pm

Hi Harbal,

Thanks, but I think I have a long way to go to match the number of laughs you have given me.

M.

duszek
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Re: falling in a vacuum container

Post by duszek » Mon Mar 06, 2017 4:10 pm

I also laughed, thank you M.

But one more thing about the dragging:

If a small parachute is attached to a heavy object they both fall together, are attracted by the gravitational force together.

What would be the shape of the parachute during the fall ? Like that of a mushroom or of a jelly-fish floating in an ocean ?
Would the shape change during the fall at all ? Or would it fall as if frozen ?

Comedy or serious contributions, both are welcome.

Grazie mille.

Metazoan
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Re: falling in a vacuum container

Post by Metazoan » Mon Mar 06, 2017 8:55 pm

Hi duszek,

Because you ask the question, it makes me think you still don't quite grasp what is going on.

Firstly, forget drag. There just isn't any.

To extend the experiment a bit, consider the heavy object as being aboard the ISS.

The ISS is accelerating towards the earth at about the same rate as the heavy object in the vacuum tube.

It is just going sideways fast enough to not quite hit the ground.

Unpack your heavy object and parachute and look at it just floating there.

The 'chute will take up whatever shape the physics of its construction dictates.

In the tube, prior to its abrupt encounter with the end, it is effectively weightless.

Does this help any?

M.

duszek
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Re: falling in a vacuum container

Post by duszek » Wed Mar 08, 2017 3:35 pm

Yes, dragging does not seem to occur at all in a vaccum tube.
Every object no matter how heavy (or rather how much mass it has) moves to the ground at exactly the same speed if the air resistance is removed. (Not exactly the same strictly speaking, but the difference is not noticeable.)

I don´t quite remember how the feather was moving to the ground: in a perfectly frozen shape or did the little parts move on the way ?

Would a piece of blanket move down in a stiff way ? As if frozen ?

The weight (and the gravitational forcee) depends on the mass of the objects concerned.
The earth should attract something huge like a moon much stronger than a pea-nut.
So a moon should move toward the earth more quickly than a pea-nut, shouldn´t it ?

Is ISS a space shuttle ? I don´t work for NASA, you know.

thedoc
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Re: falling in a vacuum container

Post by thedoc » Thu Mar 09, 2017 4:40 am

duszek wrote: The weight (and the gravitational forcee) depends on the mass of the objects concerned.
The earth should attract something huge like a moon much stronger than a pea-nut.
So a moon should move toward the earth more quickly than a pea-nut, shouldn´t it ?
Yes, the gravitational attraction is proportional to the mass, so the Moon would be attracted more strongly than the Pea-nut but the Pea-nut has less mass so the falling would be equal in a vacuum. It is air resistance that makes the difference, no air no difference.

thedoc
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Re: falling in a vacuum container

Post by thedoc » Thu Mar 09, 2017 4:47 am

duszek wrote: Is ISS a space shuttle ? I don´t work for NASA, you know.
The ISS is the International Space Station, the shuttle is used to get to and from the ISS.

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