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Posted
Just now, Itoero said:

huh? I didn't say it's floating.

If you jump off a building with a table, both, you and it, will either fall freely (because there's nothing to stop it) or float (because there is something to stop it).

Posted
4 minutes ago, DrKrettin said:

Because he jumps off the building on a table, so he and the table are in freefall, unless you want to consider the surfing properties of the table

This means he jumps from a building on a table which is on the floor.

Posted
3 minutes ago, Itoero said:

This means he jumps from a building on a table which is on the floor.

I understand it that he jumps off the building whilst standing on the table. How else who you understand it?

Posted
3 minutes ago, dimreepr said:

If you jump off a building with a table, both, you and it, will either fall freely (because there's nothing to stop it) or float (because there is something to stop it).

I don't understand your point. People do a roll to survive jumps from high heights.

 

Posted
Just now, Itoero said:

I don't understand your point. People do a roll to survive jumps from high heights.

 

But you're ignoring the OP; imagine the table is ice and you're wearing ice hockey skates, what do you think would happen if you try and jump with a 45 degree attitude? 

 

Posted
4 minutes ago, DrKrettin said:

I understand it that he jumps off the building whilst standing on the table. How else who you understand it?

I think he means you jump on a table which is on the floor, the table doesn't fall.  If he did jump of a table on a building then the table would remain on the building.

Posted
1 minute ago, Itoero said:

I think he means you jump on a table which is on the floor, the table doesn't fall.  If he did jump of a table on a building then the table would remain on the building.

The OP is really unclear. But with respect, if you don't use prepositions accurately there is no chance of getting clarity. Do you mean "onto a table" and "off  a table"?

Posted
4 minutes ago, dimreepr said:

But you're ignoring the OP; imagine the table is ice and you're wearing ice hockey skates, what do you think would happen if you try and jump with a 45 degree attitude? 

 

Why is the table  ice? And the material of the table doesn't matter since he jumped of the table before impact.

Posted
2 minutes ago, Itoero said:

I think he means you jump on a table which is on the floor, the table doesn't fall.  If he did jump of a table on a building then the table would remain on the building.

Ok let's imagine your miss-interpretation of what's clearly written is true; essentially the same thing would happen, the table would break and you'd fall flat on your face, at speed. 

Posted
1 minute ago, DrKrettin said:

The OP is really unclear. But with respect, if you don't use prepositions accurately there is no chance of getting clarity. Do you mean "onto a table" and "off  a table"?

That's true. I just think he would say it differently if the table also fell from the building.

Posted
3 minutes ago, Itoero said:

That's true. I just think he would say it differently if the table also fell from the building.

Quote

So if a person were to jump of a building of some considerable height (say 10 stories) but on a table, and he jumps of the table before impact, would he survive or not. I feel he wouldn't, but i wanted your opinion.

4

It seems clear to me, if the table was on the floor how could he jump off it BEFORE IMPACT???

Posted
2 minutes ago, dimreepr said:

Ok let's imagine your miss-interpretation of what's clearly written is true; essentially the same thing would happen, the table would break and you'd fall flat on your face, at speed. 

It's not me that's miss interprating  that's what written :) If your idea is correct the OP would have said:  "He jumps off a table, on top of a building".

So you deny that you can absorb the impact with a roll?

Posted
4 minutes ago, Itoero said:

It's not me that's miss interprating  that's what written :) If your idea is correct the OP would have said:  "He jumps off a table, on top of a building".

2

LOL, if you say so... :rolleyes:

Either way, there is no table to jump off before impact.

12 minutes ago, Itoero said:

So you deny that you can absorb the impact with a roll?

 

When did I say that?

Posted

It's obvious the OP means a cartoon style jump off of the table that is falling with him.    We had this in the other thread where it was pretty much concluded that, unless you were a cartoon rabbit, it would make sod all difference. If you were to lay on top of the table then the table might absorb some of the impact under you as it collapses under your weight.

The following suggests that if you can use the table to surf your way to a bush or a haystack or something else that can cushion your fall then that would be your best bet.

http://listverse.com/2013/09/23/10-people-who-survived-falling-from-extreme-heights/

 

 

 

 

Posted

It doesn't matter if he jumped from the table and the table fell with him or not. It's about that he jumped from the table before impact which is impossible since jumping also gives an impact...by jumping you increase the total impact.

1 hour ago, DrP said:

The following suggests that if you can use the table to surf your way to a bush or a haystack or something else that can cushion your fall then that would be your best bet.

in a haystack? so Assassin's Creed -style? :) 

Posted
Just now, Itoero said:

It doesn't matter if he jumped from the table and the table fell with him or not. It's about that he jumped from the table before impact which is impossible since jumping also gives an impact...by jumping you increase the total impact.

 

??wot??  He jumps UP off of the table as it is falling, just before it hits the ground. By jumping UP he is now moving DOWN more slowly than when he was before the jump.  However, due to the fact that the table is falling too, then the UPwards push from the table is quite small (because it is not on the ground, so it only has the air resistance to push UP onto the person not the push from the floor).   This is visualised in the cartoons where Bugs Bunny often steps off of a falling table JUST before he hits the ground.

So - by attempting to jump up from the table the table itself will hit the ground faster than it would have if you hadn't jumped...  and you will hit the ground (almost negligibly) slower. It would be best to use the table top and legs as crumple zones prior to your impact to the ground to absorb some of the impact. I still think you would be in for a lousy time of it though.

 

 

 

Posted

You give the table a downward impulse and you slow yourself down in the process. I have actually seen the practical application of this, albeit not in a vertical direction but horizontal. Here we have plenty of lizards which can descend vertical walls quite quickly with the following technique: they drop off the wall and further down they flick their tails out away from the wall. The body of the lizard gets an equal an opposite impulse towards the wall, which they can then grab with all four feet and cling on. Their tails are quite large, so flicking them gives quite an effective impulse.

Same principle, anyway.

Posted
22 hours ago, Itoero said:

It's not me that's miss interprating  that's what written :) If your idea is correct the OP would have said:  "He jumps off a table, on top of a building".

So you deny that you can absorb the impact with a roll?

You are wrong. Re-read the OP. he clearly means what we're talking about.

It makes no sense to ask what would happen if you jumped onto a table from a building but jumped off the table before impact. It makes no sense. You are misinterpreting it. Obviously, the person would just crash trough the table in that case and wouldn't be able to jump off of it.

 

22 hours ago, DrKrettin said:

This is not correct. If you and the table are in free fall, if you give the table an impulse downwards, the table gives you an equal and opposite impulse upwards. This will reduce the downward speed, although it won't make any difference to the outcome.

Are you sure about that? You exert no weight on the table. Maybe if you were crouching on it so you could exert weight by raising up. If your legs were completely straight, would you be able to lower them and thrust the table downwards?

Posted
3 minutes ago, Lord Antares said:

Are you sure about that? You exert no weight on the table. Maybe if you were crouching on it so you could exert weight by raising up. If your legs were completely straight, would you be able to lower them and thrust the table downwards?

Yes, I'm sure about that. If as you say, you crouch on the table then thrust the table downwards by stretching your legs, you impart an impulse to the table and the table gives you an equal and opposite impulse upwards. This will slow you down. I doubt whether you would disagree with the situation if there were a rocket  falling backwards towards earth which then ignites its engines and provides a thrust upwards slowing the rocket's descent. It's the same principle.

  • 2 weeks later...
Posted
On ‎19‎-‎9‎-‎2017 at 3:56 PM, Lord Antares said:

You are wrong. Re-read the OP. he clearly means what we're talking about.

It makes no sense to ask what would happen if you jumped onto a table from a building but jumped off the table before impact. It makes no sense. You are misinterpreting it. Obviously, the person would just crash trough the table in that case and wouldn't be able to jump off of it.

So you think that makes more sense?  According to the OP you jump from the table before impact, this implies that you and the table just fall from a high building. This is not a brain teaser...

Posted
16 hours ago, Itoero said:

So you think that makes more sense?  According to the OP you jump from the table before impact, this implies that you and the table just fall from a high building. This is not a brain teaser...

Yes, that's what we are saying, not what you are saying.

Posted (edited)

I'm amazed this topic has reached 46 posts, :o the physics are basic and the OP's intent is obvious; as I've previously suggested the most promising outcome involves surfing and hedges... 

Edited by dimreepr
Posted

The presence of the table doesn't add anything to the 'story' since you jump from the table before impact. He might as well have asked: "What's the chance of surviving a (10 story)building jump?" I don't think it was his intent to add things like a hedge. If you can add things then I would add a deep swimming pool.

Posted
14 minutes ago, Itoero said:

The presence of the table doesn't add anything to the 'story' since you jump from the table before impact. He might as well have asked: "What's the chance of surviving a (10 story)building jump?" I don't think it was his intent to add things like a hedge. If you can add things then I would add a deep swimming pool.

Add what you want, it doesn't change the fundamentals; physics is physics whatever you add... 

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