Intercontinental ballistic missile

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sceptimatic

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Re: Intercontinental ballistic missile
« Reply #570 on: January 15, 2019, 10:29:04 AM »
You can easily test this by yourself. Get in a wagon with a heavy rock. The heave the rock off the back of the wagon. You and the wagon will move forward.
Of course because the rock displaces a lot of atmosphere. That atmosphere pushes back. It compresses back onto that rock.
You throw that rock and you effectively have leverage against that atmospheric pressure. You push that rock one way and the wagon moves a little the other way.

Push that rock against no resistance and you go nowhere.

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JCM

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Re: Intercontinental ballistic missile
« Reply #571 on: January 15, 2019, 10:29:22 AM »
That same wagon with a person and a heavy rock are moving at a velocity on a very low friction track, the person lifts the rock and simply drops the rock behind him, the person does not throw it, no added force applied to the rock, simply lets go,  what happens to the man and the wagon? 

Do they decellerate (velocity decreases) all of a sudden due to less mass/volume/whatever pushing on the air so less “inertia/momentum/fill in your word”? And why?

Do they stay the same velocity?  And why?

Do they speed up all of a sudden due to less mass/volume/whatever? And why?

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sceptimatic

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Re: Intercontinental ballistic missile
« Reply #572 on: January 15, 2019, 10:40:59 AM »
That same wagon with a person and a heavy rock are moving at a velocity on a very low friction track, the person lifts the rock and simply drops the rock behind him, the person does not throw it, no added force applied to the rock, simply lets go,  what happens to the man and the wagon? 

Do they decellerate (velocity decreases) all of a sudden due to less mass/volume/whatever pushing on the air so less “inertia/momentum/fill in your word”? And why?

Do they stay the same velocity?  And why?

Do they speed up all of a sudden due to less mass/volume/whatever? And why?
The same I should imagine.

One balances the other out.

One one hand you have the wagon and man plus rock against the ground friction and also pushing into atmospheric friction under a set speed.
Drop the rock and you reduce the ground friction but also reduce the force effect into the atmospheric friction.

Basically no change.
It would be a different story if under power.


Re: Intercontinental ballistic missile
« Reply #573 on: January 15, 2019, 10:51:13 AM »
Of course because the rock displaces a lot of atmosphere. That atmosphere pushes back. It compresses back onto that rock.
You throw that rock and you effectively have leverage against that atmospheric pressure. You push that rock one way and the wagon moves a little the other way.

Push that rock against no resistance and you go nowhere.

Well you're almost there Scepti.  But its not the atmosphere.  Think of it this way. Assume when we shove a round spherical rock off the wagon it is free to roll on a flat surface. Then the wagon will roll in the opposite direction as the rock, and the momentum of you and the wagon in one direction will be essentially equal to the momentum of the rock in the other direction.

Sure, a tiny bit of energy is lost due to the rock moving air out of its path, but virtually all of the work applied to the pushing on the rock is now in the form of the rock's rolling kinetic energy.  And the opposing force of the push has caused you and the wagon to have approximately the same kinetic energy .

Re: Intercontinental ballistic missile
« Reply #574 on: January 15, 2019, 10:57:47 AM »
That same wagon with a person and a heavy rock are moving at a velocity on a very low friction track, the person lifts the rock and simply drops the rock behind him, the person does not throw it, no added force applied to the rock, simply lets go,  what happens to the man and the wagon? 

Do they decellerate (velocity decreases) all of a sudden due to less mass/volume/whatever pushing on the air so less “inertia/momentum/fill in your word”? And why?

Do they stay the same velocity?  And why?

Do they speed up all of a sudden due to less mass/volume/whatever? And why?

The rock and the wagon would continue on at the same velocity. There has been no force applied either for or against the forward motion, therefore no change in velocity or momentum (ignoring, as you say, frictional affects)

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sceptimatic

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Re: Intercontinental ballistic missile
« Reply #575 on: January 15, 2019, 11:05:50 AM »
Of course because the rock displaces a lot of atmosphere. That atmosphere pushes back. It compresses back onto that rock.
You throw that rock and you effectively have leverage against that atmospheric pressure. You push that rock one way and the wagon moves a little the other way.

Push that rock against no resistance and you go nowhere.

Well you're almost there Scepti.  But its not the atmosphere.  Think of it this way. Assume when we shove a round spherical rock off the wagon it is free to roll on a flat surface. Then the wagon will roll in the opposite direction as the rock, and the momentum of you and the wagon in one direction will be essentially equal to the momentum of the rock in the other direction.

Sure, a tiny bit of energy is lost due to the rock moving air out of its path, but virtually all of the work applied to the pushing on the rock is now in the form of the rock's rolling kinetic energy.  And the opposing force of the push has caused you and the wagon to have approximately the same kinetic energy .
It makes no sense.
If you have nothing to push that rock into then you have to leverage to push you in the opposite direction. It's all about displacing an amount of atmospheric pressure by pushing the object against it to create an opposite effect.

Take away the resistive force and you have nothing to push against.
Have you ever tried to cycle against the wind?

All you're doing is creating that same effect by compression of your push against atmosphere.
Anyone being in the path of the rock would feel a wind force from that compression of atmosphere you threw the rock into and that compression is your leverage to push your wagon in the opposite direction by your friction grip on that wagon.


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JCM

  • 245
Re: Intercontinental ballistic missile
« Reply #576 on: January 15, 2019, 11:06:01 AM »
That same wagon with a person and a heavy rock are moving at a velocity on a very low friction track, the person lifts the rock and simply drops the rock behind him, the person does not throw it, no added force applied to the rock, simply lets go,  what happens to the man and the wagon? 

Do they decellerate (velocity decreases) all of a sudden due to less mass/volume/whatever pushing on the air so less “inertia/momentum/fill in your word”? And why?

Do they stay the same velocity?  And why?

Do they speed up all of a sudden due to less mass/volume/whatever? And why?
The same I should imagine.

One balances the other out.

One one hand you have the wagon and man plus rock against the ground friction and also pushing into atmospheric friction under a set speed.
Drop the rock and you reduce the ground friction but also reduce the force effect into the atmospheric friction.

Basically no change.
It would be a different story if under power.

Correct Answer.  Many people would guess incorrectly.  That is conservation of momentum.    You understand conservation of momentum, yet once it goes vertical, then it doesn’t work anymore in your model.

If for sake of argument, rockets were not pushing on the atmosphere, would you agree rockets work as described?

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sceptimatic

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Re: Intercontinental ballistic missile
« Reply #577 on: January 15, 2019, 11:08:04 AM »
That same wagon with a person and a heavy rock are moving at a velocity on a very low friction track, the person lifts the rock and simply drops the rock behind him, the person does not throw it, no added force applied to the rock, simply lets go,  what happens to the man and the wagon? 

Do they decellerate (velocity decreases) all of a sudden due to less mass/volume/whatever pushing on the air so less “inertia/momentum/fill in your word”? And why?

Do they stay the same velocity?  And why?

Do they speed up all of a sudden due to less mass/volume/whatever? And why?
The same I should imagine.

One balances the other out.

One one hand you have the wagon and man plus rock against the ground friction and also pushing into atmospheric friction under a set speed.
Drop the rock and you reduce the ground friction but also reduce the force effect into the atmospheric friction.

Basically no change.
It would be a different story if under power.

Correct Answer.  Many people would guess incorrectly.  That is conservation of momentum.    You understand conservation of momentum, yet once it goes vertical, then it doesn’t work anymore in your model.

If for sake of argument, rockets were not pushing on the atmosphere, would you agree rockets work as described?
Absolutely not. 100%.

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JackBlack

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Re: Intercontinental ballistic missile
« Reply #578 on: January 15, 2019, 12:19:44 PM »
If the cat jumps forward it accelerates away from the skateboard and the only way to do that is for its feet to use that skateboard as its leverage
Well thanks for finally admitting it is the skateboard that matters, not the air.
It can also do this vertically, using the skateboard as its leverage.

which means slowing the skateboard down in order to accelerate itself.
Only if it jumps of forwards. If it jumps of backwards it will accelerate the skateboard as it slows itself.

Then how about explaining how it works with a rocket vertically.
It has already been explained to you repeatedly. You just choose to remain wilfully ignorant.

How about you start explaining why vertically is magically different or why a rocket should do anything like you claim, backing it up with rational arguments and evidence?

Let's build a man sized cardboard rocket, hypothetically.
All it will be will be a tube that can fit me and you in with our feet soles touching, knees bent and our heads touching a closed lid on each side of the tube.
I'll liken this to how your rocket works.
Do you agree with this part?
We would be the fuel under pressure.
If I push into you, you push into me.
Your head goes to the top head and mine goes to the bottom, exhaust.
Am I on the right lines with your rocket?
If I am then I'll carry on. If not, tell me why not.
No, what rocket do you see burning without having the exhaust go out the bottom?
That would be a firecracker.
Try it this way:
Only the top is closed.
He starts up against the top. You start directly below him.
You then push off him.
That results in you being pushed down and him being pushed up. He is contact with the rocket and thus pushes it up as well.
You then fly out the bottom of the tube.

We both start to stretch out but that results in me being pushed out by you using your head against the top of your rocket and me simply having nothing to push against you, so I merely fall out and your head simply uses the rocket top as a leverage to push me out. It does not move your rocket.
Pure bullshit.
Why does it move him in the first instance, but then magically not in the second?
You started off well. You push against each other and you both move.
Remember, action and reaction?

It doesn't matter who pushes who as every action has an equal and opposite reaction.


I resisted by having something outside to push into
You resist by existing. You don't need a magical atmosphere to resist against you, unless you want to claim you can accelerate objects with no force required if the atmosphere isn't there.
If the latter then the rocket doesn't need a force to accelerate.

You see, if I don't have something to resist my push against your push then your push is pointless.
Can you see what I'm saying?
Yes, we all see what you are saying. You are baselessly spouting crap which isn't backed up by any evidence at all.
Stop just baselessly asserting garbage.
We also see you running off on another pathetic distraction.
The question you were trying to respond to wasn't why doesn't it work in space, it is why doesn't it work vertically.

It makes no sense.
No, the crap you are spouting makes no sense.
You are yet to show an issue with real physics. Instead all you have are your repeated lies, which aren't even consistent.

It's all about displacing an amount of atmospheric pressure by pushing the object against it to create an opposite effect.
If that was the case the object would move while being pushed and then stop dead.
Once you stop pushing it doesn't magically stop displacing the atmosphere. So by your reasoning, with displacing the atmosphere being the only reason it needs a force, then it still needs that force to continue moving and thus once it leaves your hand or whatever and the force is not applied, it should stop dead.

But does that happen in reality? NO!
Instead it continues moving, only gradually slowing down.
This shows that while the air will result in some resistance, it doesn't provide all of it. It is the object itself resisting motion that provides the resistance.


Have you ever tried to cycle against the wind?
Yes, it is only marginally harder that cycling in still air, which is slightly harder than riding with the wind.
This shows that while the atmosphere does offer some resistance, it is not the main contributing factor.

All you're doing is creating that same effect by compression of your push against atmosphere.

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JackBlack

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Re: Intercontinental ballistic missile
« Reply #579 on: January 15, 2019, 12:23:58 PM »
A short version if you prefer:
If it is only the atmosphere resisting the motion that requires a force then all objects should stop dead in the atmosphere, regardless of how they move, as soon as they are no longer being pushed.
This would mean once you throw a ball, it stops dead as soon as it leaves your hand.
This is contradicted by countless experiments and everyday observation.

The fact that objects keep moving without a force being applied to them, even though they are displacing the atmosphere shows that there is something else, something like inertia/momentum. This means the object itself resists changes in motion.
This means if you throw it the act of accelerating it requires a force which results in a reactionary force.

Yes, the air does provide some resistance, but it is not the only factor and in lots of cases is insignificant.

If you wanted to ignore all that reality and continue with fantasy it also means without the air rockets would be able to accelerate without any force.

None of your claims (even if accepted as true) explain why vertical should be magically different, or any problem with rockets in space or ICBMs in general.

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Stash

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Re: Intercontinental ballistic missile
« Reply #580 on: January 15, 2019, 12:32:45 PM »

Your claim - The rocket springboards then has a constant velocity while the engine is on.
As long as it's at max thrust and in vertical flight.
Quote from: JackBlack
Their claim (and all the results of all experiments) - The rocket continues to accelerate while the engine is on.

Quote from: JackBlack
Your claim - After the fuel is depleted the rocket stops dead and falls.
Once under consistent speed and then with immediate thrust shut down.


Quote from: JackBlack
Their claim (and all the results of all experiments) - The rocket continues to move upwards but slows down as it does so.
This would only happen right after immediate springboard acceleration. Once into consistent speed it would not.

Quote from: JackBlack
And a bonus one:
Your claim - At the end of this thrusting portion of the flight the model rocket has stopped dead and is stationary before it falls back down to Earth.
After springboard launch and into consistent flight.
Once it's pushing it's own mass under power then that's all it pushes. Nothing more. No extra momentum.
Cut the thrust dead and you cut the rocket dead.

Quote from: JackBlack
Their claim (and the results of all experiments) - At the end of this thrusting portion of the flight the model rocket is travelling at its maximum speed.

Yep.l Which like I've said is in seconds. Apparently 1.7 seconds with their rocket. Short order for ease.

Quote from: JackBlack
Notice the massive difference between your claims and theirs?
I'd say there's a swerve on their part but it's like a boomerang, it comes right back to the crux of what I said. In bold above.

Quote from: JackBlack
So do you think these people, who have been dealing with rockets for quite some time, are just extremely stupid and ignorant and have no idea what they are talking about, or do you think they are lying? Or are you just wrong?
Far from stupid. Ignorant? It depends on who's doing what and for what purpose for video.
I don't know what the motives are for some. As for the many, I suggest they're just setting off rockets as a hobby. Why not?

I don't know what you mean by "swerve".

It's quite simple, the model rocket industry says that their rockets:
A) Take off at max thrust and burn, in this example, for 1.7 seconds (some burn durations longer, some shorter, depends on the engine)
B) The rocket is accelerating, going faster throughout the 1.7 second burn
C) The burn stops, the rocket continues to ascend under momentum
D) It reaches it's apogee, parachute pops, it floats back down

You come along and say, "No, model rocket industry, your B and C are wrong, it's a 'swerve' and you are possibly ignorant. I don't know why you claim this, but it's wrong because I said so."

This is your position with zero evidence to back up your claim?

Re: Intercontinental ballistic missile
« Reply #581 on: January 15, 2019, 12:38:00 PM »
It makes no sense.
If you have nothing to push that rock into then you have to leverage to push you in the opposite direction. It's all about displacing an amount of atmospheric pressure by pushing the object against it to create an opposite effect.

Take away the resistive force and you have nothing to push against.
Have you ever tried to cycle against the wind?

All you're doing is creating that same effect by compression of your push against atmosphere.
Anyone being in the path of the rock would feel a wind force from that compression of atmosphere you threw the rock into and that compression is your leverage to push your wagon in the opposite direction by your friction grip on that wagon.

Scepti, think of it this way.  You push on this rock and it rolls away causing your wagon to move the other way. We agree on that. Where we disagree is the role of the air resistance.

So consider this. Same wagon. Same size rock, but much heavier. You push away just as hard as before. Wagon moves away just as before.  But the rock moves much slower because of the heavier weight. The heavier the rock, the slower it would move, the less air it would push out of the way. But the wagon moves just as before. If it were the air "pushing back" there would be less and less pushback as the rock is heavier, and then how could the wagon still be moving as before.

Re: Intercontinental ballistic missile
« Reply #582 on: January 15, 2019, 12:38:27 PM »
Stops dead.

Maybe define that.
Impossible it means what we all think you mean.

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JackBlack

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Re: Intercontinental ballistic missile
« Reply #583 on: January 15, 2019, 01:02:20 PM »
So consider this. Same wagon. Same size rock, but much heavier.
He lives in a delusional fantasy land where weight and mass are based upon the amount of air displaced.
To him, it doesn't matter that the rock looks the same size and every test of its volume reveals that it displaces the same amount of air/fluid. He claims that as it is a different mass it must be a different volume.

Re: Intercontinental ballistic missile
« Reply #584 on: January 15, 2019, 04:58:37 PM »
To everyone, I'm so sorry I used my cats on the skateboard.  I used my cats in the example to lighten the mood a bit.  For get how the cats get off, which direction, etc.  The idea was to remove a weight from the skateboard with imparting any forces.  The skateboard has a constant applied force and mass if removed while the applied force remains was the point.  Forget the cats and how they get off the board.

BTW, they were Sabrina and Francis.  My daughter named the female Sabrina after the "Teenage Witch" and I named her brother Francis because he had blue eyes.



Because, those model rockets do everything you claim is impossible for a rocket to do (some of those model rockets are taller than your house).  Either your claims apply to all rockets or none of them.

I live on the top floor of 432 Park Avenue in New York City. You may need to revise your model rocket heights.  ;) :P
Okay.  Definitely not your house but certainly mine (a one floor ranch) :D

On a serious note, certain model rockets may have the ability to build up thrust for a short time to give them the power to accelerate for that period. I don't know for sure. What I'm saying is, if they launch at full thrust then they do not continue to accelerate after initial springboard launch has hit max push, which would be in a second or so.
Taking model rockets out of that equation. It would not apply to a so called ICBM or so called space rocket because a large rocket would certainly require the full might of its available thrust to catapult that rocket into the air to then simply hold a consistent speed.
Quote from: MicroBeta
You can test this...you can test all or your claims about rockets with as simple or complicated a model you want.  I don't know why you refuse to but all your claims would go from theory to fact.  I boggles my mind why you wouldn't want to test this.

Mike
Don't panic over it. You've tested nothing and if you have, show me the proof.
No need to counteract that with me by asking me to show you the proof. I don't have it.
You claim to have it, so show me it.
You know I can’t show proof.  The last time I launched models was thirty years ago.  Who would have thought I’d have to prove such a thing?

However, I’ve provided you with the tools to test my claim that you can build a model rocket with on-board guidance control and thrust vector control, will take off slowly, accelerate as it climbs, and even be able to land like the Falcon Heavy...and just like an ICBM, except for the landing part.  If you live on Park Avenue then you can certainly afford the $500-$700 it would cost.

You’ve already decided what will happen so you won’t test it.  So, all you have to go on are the videos.  BTW, the performance of model rockets is clearly scalable to larger platforms.  I say clearly because from the smallest to the largest models, they react the same regardless of size.  To take a page out of your play book...if you’re honest, you have to admit that the volume of videos and data from the thousands of rocketry clubs and vendors throughout the world provides ample evidence that it’s more likely than not that they perform as advertised.  You don’t have to agree with the claimed performance but you should admit there’s more evidence than you have.

Mike
Since it costs 1.82¢ to produce a penny, putting in your 2¢ if really worth 3.64¢.

Re: Intercontinental ballistic missile
« Reply #585 on: January 15, 2019, 05:13:01 PM »
To mikes point and maybe confusing poor scepti even more.... but figure skaters can change their angular velcoity by shiftng the mass for the outside to the inside (pulling arms or legs in).
Similar concept in linear in that a change the mass-velocity momentum where instead hes just kicking poor francis and sabrina off the skate board .

Re: Intercontinental ballistic missile
« Reply #586 on: January 15, 2019, 08:07:15 PM »
\
He lives in a delusional fantasy land where weight and mass are based upon the amount of air displaced.
To him, it doesn't matter that the rock looks the same size and every test of its volume reveals that it displaces the same amount of air/fluid. He claims that as it is a different mass it must be a different volume.

Scepti might surprise you. I will wait for his answer.

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sceptimatic

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Re: Intercontinental ballistic missile
« Reply #587 on: January 16, 2019, 02:33:13 AM »
A short version if you prefer:
If it is only the atmosphere resisting the motion that requires a force then all objects should stop dead in the atmosphere, regardless of how they move, as soon as they are no longer being pushed.
Vertically, yes, as long as the object in motion, VERTICALLY is under its own consistent power/thrust.
This does not apply horizontally for reasons I explained.

Quote from: JackBlack
This would mean once you throw a ball, it stops dead as soon as it leaves your hand.
This is contradicted by countless experiments and everyday observation.

Nope, not at all.
Once you throw the ball you accelerate it to a peak speed.
Once that peak speed is achieved it slows against resistance before stopping and accelerating back down.

Totally different to what I'm saying and I'm sure you know this.


Quote from: JackBlack
.

None of your claims (even if accepted as true) explain why vertical should be magically different, or any problem with rockets in space or ICBMs in general.
Yep, my explanations are fine. You accepting them or not is a different matter but not my issue.

Re: Intercontinental ballistic missile
« Reply #588 on: January 16, 2019, 02:52:25 AM »
Interesting.
Peak is what we ve been saying all along.
Now your story has changed...

So if we are in somewht agreement.

Please define dead stop when trust = zero.
Because that is contrary to what we all understand as dead stop when accell = zero.
Like i mentioned a bunch of times.
You have velocity in the bank.

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JackBlack

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Re: Intercontinental ballistic missile
« Reply #589 on: January 16, 2019, 04:37:53 AM »
This does not apply horizontally for reasons I explained.
No you haven't.
You just assert it and then run off on a tangent.
You are yet to explain why vertical should be magically different.

Nope, not at all.
Once you throw the ball you accelerate it to a peak speed.
Once that peak speed is achieved it slows against resistance before stopping and accelerating back down.
Again, that literally literally makes no sense.
You are still displacing the atmosphere and thus in order for you to be consistent you must have the object stop dead as it is no longer being provided with any force to keep it going.
The other other way out is to discard your claims about the atmosphere causing the resistance and instead accept that the object itself is and it is accelerating the object that requires the force, and then once it is moving it keeps going until a force stops it.

They are the only options.
If you think you have an alternative, feel free to provide it, clearly explaining how it works.

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sceptimatic

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Re: Intercontinental ballistic missile
« Reply #590 on: January 16, 2019, 11:31:45 AM »
It's quite simple, the model rocket industry says that their rockets:
A) Take off at max thrust and burn, in this example, for 1.7 seconds (some burn durations longer, some shorter, depends on the engine)
B) The rocket is accelerating, going faster throughout the 1.7 second burn
C) The burn stops, the rocket continues to ascend under momentum
D) It reaches it's apogee, parachute pops, it floats back down

You come along and say, "No, model rocket industry, your B and C are wrong, it's a 'swerve' and you are possibly ignorant. I don't know why you claim this, but it's wrong because I said so."

This is your position with zero evidence to back up your claim?
I said the rocket accelerates for a second or so.
Did I not say that?


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sceptimatic

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Re: Intercontinental ballistic missile
« Reply #591 on: January 16, 2019, 11:35:03 AM »
It makes no sense.
If you have nothing to push that rock into then you have to leverage to push you in the opposite direction. It's all about displacing an amount of atmospheric pressure by pushing the object against it to create an opposite effect.

Take away the resistive force and you have nothing to push against.
Have you ever tried to cycle against the wind?

All you're doing is creating that same effect by compression of your push against atmosphere.
Anyone being in the path of the rock would feel a wind force from that compression of atmosphere you threw the rock into and that compression is your leverage to push your wagon in the opposite direction by your friction grip on that wagon.

Scepti, think of it this way.  You push on this rock and it rolls away causing your wagon to move the other way. We agree on that. Where we disagree is the role of the air resistance.

So consider this. Same wagon. Same size rock, but much heavier. You push away just as hard as before. Wagon moves away just as before.  But the rock moves much slower because of the heavier weight. The heavier the rock, the slower it would move, the less air it would push out of the way. But the wagon moves just as before. If it were the air "pushing back" there would be less and less pushback as the rock is heavier, and then how could the wagon still be moving as before.
The heavier rock is that way because it has more mass and displaces more atmosphere and in essence will act on you trying to throw it, which is why it is harder to pick up and throw, due to that extra displacement.

Re: Intercontinental ballistic missile
« Reply #592 on: January 16, 2019, 11:39:12 AM »
It makes no sense.
If you have nothing to push that rock into then you have to leverage to push you in the opposite direction. It's all about displacing an amount of atmospheric pressure by pushing the object against it to create an opposite effect.

Take away the resistive force and you have nothing to push against.
Have you ever tried to cycle against the wind?

All you're doing is creating that same effect by compression of your push against atmosphere.
Anyone being in the path of the rock would feel a wind force from that compression of atmosphere you threw the rock into and that compression is your leverage to push your wagon in the opposite direction by your friction grip on that wagon.

Scepti, think of it this way.  You push on this rock and it rolls away causing your wagon to move the other way. We agree on that. Where we disagree is the role of the air resistance.

So consider this. Same wagon. Same size rock, but much heavier. You push away just as hard as before. Wagon moves away just as before.  But the rock moves much slower because of the heavier weight. The heavier the rock, the slower it would move, the less air it would push out of the way. But the wagon moves just as before. If it were the air "pushing back" there would be less and less pushback as the rock is heavier, and then how could the wagon still be moving as before.
The heavier rock is that way because it has more mass and displaces more atmosphere and in essence will act on you trying to throw it, which is why it is harder to pick up and throw, due to that extra displacement.
How can 2 objects the same size but different materials displace a different volume of atmosphere?  The only volume is that of the object.

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sceptimatic

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Re: Intercontinental ballistic missile
« Reply #593 on: January 16, 2019, 11:39:55 AM »


You’ve already decided what will happen so you won’t test it.  So, all you have to go on are the videos.  BTW, the performance of model rockets is clearly scalable to larger platforms.  I say clearly because from the smallest to the largest models, they react the same regardless of size.  To take a page out of your play book...if you’re honest, you have to admit that the volume of videos and data from the thousands of rocketry clubs and vendors throughout the world provides ample evidence that it’s more likely than not that they perform as advertised.  You don’t have to agree with the claimed performance but you should admit there’s more evidence than you have.

Mike
If that's what you think then I have no authority over that.
I don't think there's more evidence in favour of what you say. I do accept that there is a lot more storylines on it.
That doesn't make a truth, though.


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sceptimatic

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Re: Intercontinental ballistic missile
« Reply #594 on: January 16, 2019, 11:43:03 AM »
So consider this. Same wagon. Same size rock, but much heavier.
He lives in a delusional fantasy land where weight and mass are based upon the amount of air displaced.
To him, it doesn't matter that the rock looks the same size and every test of its volume reveals that it displaces the same amount of air/fluid. He claims that as it is a different mass it must be a different volume.
I claim it because I believe it to be true.
A hollow block the same size as a solid block will look like they're both the same until you pick them up to find their volumes are different.


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sceptimatic

  • Flat Earth Scientist
  • 30059
Re: Intercontinental ballistic missile
« Reply #595 on: January 16, 2019, 11:54:54 AM »
Interesting.
Peak is what we ve been saying all along.
Now your story has changed...

So if we are in somewht agreement.

Please define dead stop when trust = zero.
Because that is contrary to what we all understand as dead stop when accell = zero.
Like i mentioned a bunch of times.
You have velocity in the bank.
Yes you have velocity in the bank, horizontally.
We are talking about vertically and it's as simple as this.

If your rocket accelerates and stops dead it will still have the momentum from that initial acceleration. The springboard effect to carry it forward.

I have no issues with this.

What I do have issues with is the consistent speed from that point of mass thrust after acceleration.
All the rocket is doing from that point, is keeping its own mass aloft and pushing its own mass with max thrust to keep a consistent speed against that portion of atmosphere it is in at every millimetre of movement.

If you cut the thrust dead from any point during that push, the rocket stops dead and accelerates back down. It does not travel any further forward, vertically.


To understand this just think of an elevator at a consistent speed going up. If that cable snaps the elevator does not advance, It stops dead and then accelerates down  until it hits the bottom or brakes are used.


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Stash

  • Ethical Stash
  • 13398
  • I am car!
Re: Intercontinental ballistic missile
« Reply #596 on: January 16, 2019, 12:00:47 PM »
It's quite simple, the model rocket industry says that their rockets:
A) Take off at max thrust and burn, in this example, for 1.7 seconds (some burn durations longer, some shorter, depends on the engine)
B) The rocket is accelerating, going faster throughout the 1.7 second burn
C) The burn stops, the rocket continues to ascend under momentum
D) It reaches it's apogee, parachute pops, it floats back down

You come along and say, "No, model rocket industry, your B and C are wrong, it's a 'swerve' and you are possibly ignorant. I don't know why you claim this, but it's wrong because I said so."

This is your position with zero evidence to back up your claim?

I said the rocket accelerates for a second or so.
Did I not say that?

Did you not read what I wrote above? "(some burn durations longer, some shorter, depends on the engine)"

Estes E class 24 mm engines, for example, have a burn time just above 3 seconds.

And again, is your claim that the model rocket industry is wrong about their claim of B & C? If so, what is your evidence for them being incorrect?

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sceptimatic

  • Flat Earth Scientist
  • 30059
Re: Intercontinental ballistic missile
« Reply #597 on: January 16, 2019, 12:03:46 PM »
Nope, not at all.
Once you throw the ball you accelerate it to a peak speed.
Once that peak speed is achieved it slows against resistance before stopping and accelerating back down.
Again, that literally literally makes no sense.
You are still displacing the atmosphere and thus in order for you to be consistent you must have the object stop dead as it is no longer being provided with any force to keep it going.
Absorb this.

You use your energy to throw the ball vertically. You accelerate that ball until you let go at peak acceleration.
From that point the ball will use the momentum from that acceleration against the friction of the atmosphere that slows it down.
It still advances vertically until that atmospheric friction stops that momentum from that applied energy to accelerate the object.


But this isn't what we are arguing about.
What we are arguing about is something under power. Something under max thrust and a continuation of max thrust against the friction of atmosphere.


Quote from: JackBlack

The other other way out is to discard your claims about the atmosphere causing the resistance and instead accept that the object itself is and it is accelerating the object that requires the force, and then once it is moving it keeps going until a force stops it.

They are the only options.
If you think you have an alternative, feel free to provide it, clearly explaining how it works.
I've explained. Feel free to deny it.

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sceptimatic

  • Flat Earth Scientist
  • 30059
Re: Intercontinental ballistic missile
« Reply #598 on: January 16, 2019, 12:06:54 PM »
It makes no sense.
If you have nothing to push that rock into then you have to leverage to push you in the opposite direction. It's all about displacing an amount of atmospheric pressure by pushing the object against it to create an opposite effect.

Take away the resistive force and you have nothing to push against.
Have you ever tried to cycle against the wind?

All you're doing is creating that same effect by compression of your push against atmosphere.
Anyone being in the path of the rock would feel a wind force from that compression of atmosphere you threw the rock into and that compression is your leverage to push your wagon in the opposite direction by your friction grip on that wagon.

Scepti, think of it this way.  You push on this rock and it rolls away causing your wagon to move the other way. We agree on that. Where we disagree is the role of the air resistance.

So consider this. Same wagon. Same size rock, but much heavier. You push away just as hard as before. Wagon moves away just as before.  But the rock moves much slower because of the heavier weight. The heavier the rock, the slower it would move, the less air it would push out of the way. But the wagon moves just as before. If it were the air "pushing back" there would be less and less pushback as the rock is heavier, and then how could the wagon still be moving as before.
The heavier rock is that way because it has more mass and displaces more atmosphere and in essence will act on you trying to throw it, which is why it is harder to pick up and throw, due to that extra displacement.
How can 2 objects the same size but different materials displace a different volume of atmosphere?  The only volume is that of the object.
Can a sponge displace the same amount of atmosphere as a block of lead of equal size?
Answer that and you have a chance of understanding. It's not as though you haven't been told this before.

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sceptimatic

  • Flat Earth Scientist
  • 30059
Re: Intercontinental ballistic missile
« Reply #599 on: January 16, 2019, 12:08:46 PM »
It's quite simple, the model rocket industry says that their rockets:
A) Take off at max thrust and burn, in this example, for 1.7 seconds (some burn durations longer, some shorter, depends on the engine)
B) The rocket is accelerating, going faster throughout the 1.7 second burn
C) The burn stops, the rocket continues to ascend under momentum
D) It reaches it's apogee, parachute pops, it floats back down

You come along and say, "No, model rocket industry, your B and C are wrong, it's a 'swerve' and you are possibly ignorant. I don't know why you claim this, but it's wrong because I said so."

This is your position with zero evidence to back up your claim?

I said the rocket accelerates for a second or so.
Did I not say that?

Did you not read what I wrote above? "(some burn durations longer, some shorter, depends on the engine)"

Estes E class 24 mm engines, for example, have a burn time just above 3 seconds.

And again, is your claim that the model rocket industry is wrong about their claim of B & C? If so, what is your evidence for them being incorrect?
Show me the engine of a model rocket.