If it doesn't agree with experiment, it's wrong. Part II

[Giordano]

My apologies for not rereading the entire thread, but has anyone else already pointed out that the proper title for the OP is "If Falseflag doesn't agree with experiment, it's wrong."?

 

[FalseFlag]

My point is that you don't know the answer to those questions, when you try to work it out you get it wrong, and when anyone points out that you got it wrong you insist you're right because you know better than everyone else. You've found out you were wrong about gravity; try to consider the possibility that you're equally wrong about adding and subtracting forces.

Dave

If you claim I'm wrong, prove I'm wrong.

You have refused to point out a statement of mine and explain why it is wrong. Instead, you attack me globally and ask me to answer your questions. I will not do this. If you claim I'm wrong, show why I am wrong. Please provide a link to a credible source that shows exactly which statement or concept is wrong.

If I don't understand something, then show me what I don't understand. Stop making claims without proof.

 

[FalseFlag]

My apologies for not rereading the entire thread, but has anyone else already pointed out that the proper title for the OP is "If Falseflag doesn't agree with experiment, it's wrong."?

Show me an experiment that proves Cole is wrong. If you can't do that, your post is meaningless.

 

[FalseFlag]

Myriad has already explained where your mistake is: the two forces are not a reaction pair. Newton's law does NOT apply to them. They thus do not need to be equal, even if they "can", whatever the hell that means.

What forces are not an action-reaction pair?

But don't you see that the two aren't the same? Or is turning sufficient?

They don't have to be the same if you are describing similar directions of motion.

This seems to be your M.O., here. Perpetually pretend to never have read any argument or statement, and constantly ask other posters to do the same work over and over while you continue to ignore it.

What legitimate work have I ignored?

 

[NoahFence]

If you claim I'm wrong, prove I'm wrong.

You have refused to point out a statement of mine and explain why it is wrong. Instead, you attack me globally and ask me to answer your questions. I will not do this. If you claim I'm wrong, show why I am wrong. Please provide a link to a credible source that shows exactly which statement or concept is wrong.

If I don't understand something, then show me what I don't understand. Stop making claims without proof.

There is so much wrong in everything you post, where do we start?

How about the basics, simple yes or no:

Aircraft impacts + Fire caused the Twin Towers to collapse, and nothing more.

Yes or no?

If no, please explain in YOUR words what YOU THINK happened.

 

[FalseFlag]

So then it clearly has nothing to do with any conspiracies of Truther claims, so why is this thread in this forum?

Your post makes no sense. Cole's experiments are relevant to 9/11. They belong in this forum, even though you don't agree with them.

 

[FalseFlag]

There is so much wrong in everything you post, where do we start?

How about the basics, simple yes or no:

Aircraft impacts + Fire caused the Twin Towers to collapse, and nothing more.

Yes or no?

If no, please explain in YOUR words what YOU THINK happened.

You can claim whatever you want caused the towers to collapse. Perform an experiment to replicate the motion. If you don't want to perform an experiment, then maybe you can find an experiment that does replicate the observed motions in the collapse of WTC1 and WTC2.

Post the experiment that replicates the observed motions of the collapses once you find it.

 

[FalseFlag]

I explained that before and you just farted in my general direction. In the collisions, the action-reaction pair of contact forces are caused by (but are not the same thing as) the combined forces of gravity and inertia. The actual force that's applied to the structure below, however, is limited by how much force the structure can sustain. If it can absorb the combined forces of gravity and inertia without failing, then the collapse halts; otherwise it continues. Now here's where the difference between "caused by" and "same thing as" matters: The actual force that gets applied to the structure below cannot exceed the force that it takes to collapse the structure, because that's the maximum reaction force that the structure can provide. Whatever that reaction force is at the time the structure fails, that's all the force that acts to slow the falling mass, regardless of how much force is available from gravity and inertia.

Nonsense. Your post is word salad with only one purpose. The purpose is to make simple concepts seem complicated.

 

[NoahFence]

You can claim whatever you want caused the towers to collapse. Perform an experiment to replicate the motion. If you don't want to perform an experiment, then maybe you can find an experiment that does replicate the observed motions in the collapse of WTC1 and WTC2.

Post the experiment that replicates the observed motions of the collapses once you find it.

It was a yes or no question.

 

[FalseFlag]

That in order to avoid confusion THEY DON'T USE THE AMBIGUOUS TERM "DECELLERATION".

I have already defined deceleration, and I have provided a link to my source.

 

[sts60]

Wrong. Equal and opposite have nothing to do with one object breaking another. Those are separate concepts.

I didn't say what you just said. What I have said, in several different ways, is that unless there is a net upward force on the brick, the brick won't slow down. This is literally 8th-grade stuff.

You assume that because gravity always causes the brick to accelerate downwards at g,

No. The brick will only accelerate downwards at g in the absence of other forces.

the force exerted by the brick is not enough to change the acceleration.

That's not what I said. It doesn't even make enough sense to be wrong.

The velocity of a falling brick increases over time. This is because of the acceleration due to gravity.

Correct.

At a given instant, the brick impacts a piece of rice paper. Newton's third law tells us what must happen. At the instant of impact, the brick will exert a force on the rice paper. The rice paper will exert an equal force on the brick in the opposite direction.

Correct, in the simplifying sense that we're treating the brick and rice paper as simple interacting objects.

This force, in the opposite direction of travel, must change the velocity of the brick. It has to. If the velocity changes for an instant, then acceleration must change. If the velocity has decreased with respect to time, the brick has experienced a deceleration.

This is where you go off the rails. The force must change the acceleration of the brick. Since we agree in this scenario that the tissue/rice paper/whatever cannot hold the brick's weight in a static scenario, then the net force on the brick must still be downward, and the brick is still accelerating downward.

You're doing two things wrong:

(1) You're putting the cart before the horse in talking about the velocity changing the acceleration. The net force on the brick changes the acceleration, which over time will change the velocity.

(2) The explicit error is where you assert that the velocity has decreased during the impact. It hasn't; it can't decrease because the acceleration is still "downward" during the impact,
because the net force on the brick is still downward,
because the upward force exerted on the brick by the tissue must be less than the weight of the brick,
because we know from the problem statement that the tissue/rice paper/whatever can't hold the static weight of the brick.

I'm not sure where your misunderstanding is coming from. It's almost as if you take "equal and opposite" reactions between the brick and the paper/tissue to mean that the tissue exerts a force equal and opposite to the force of gravity on the brick. This is impossible according to the problem statement, but even if it was "equal and opposite", the brick would maintain its downward speed during the impact, not slow down.

After the instant of impact, the rice paper is no longer in the path of travel. The velocity of the brick will then start to increase again.

The speed of the brick will continue to increase, at g again.

Your argument is the paper has to exert a large enough force to cause a noticeable change in the velocity of the brick. This is not true...

Of course it's not true; I said no such thing. Whether it's noticeable or not is completely irrelevant.

... If the paper is being supported by something, then the normal forces are balanced. Stop making things needlessly complex.

In this problem, it is implicit that the paper/tissue is fixed at the edges. Why are you even bringing it up? It has nothing to do with the forces exerted between it and the brick.

When you do that it prevents you from easily understanding easy concepts.

You are stubbornly repeating a fundamental misunderstanding of an 8th-grade problem. I recommend you stop lecturing others (including, but not limited to, those of us with actual physics degrees) about their perceived failures of understanding, and start addressing your own.

 

[Myriad]

I agree that your model is more correct, when Newton's third law is being discussed.

You are right that I had a misconception about all of the forces involved when discussing Newton's third law of motion.

The most simple way to explain it is, if the forces are acting on one object, they are not action-reaction pairs.

Once again, you were right, and I did misunderstand this one concept.



Should we ignore air resistance? I think your example requires me to.

The equal and opposite force is the force the skydiver exerts on the earth. The earth's gravity pulls the skydiver down, and the skydiver pulls the earth towards himself or herself. Since the forces are equal (but opposite), and the mass of the earth is so much greater than that of the skydiver, the acceleration of the earth towards the skydiver is negligible. It's there, but unnoticeable.

One last time, you were right about action-reaction pairs.
I emphasized that last statement as much as I could so you could gloat as much as possible. You skeptics aren't right too often, so you really should enjoy this one as much as you can.

FalseFlag, I commend you for this.

Oh, not for realizing you were wrong and admitting it. (You knew you were wrong all along, of course.)

Rather, for the timing and brilliance of the play, and your ongoing artistry in continuing to elicit serious responses.

I'll be watching with respectful admiration as you continue to convince reasonably intelligent people that you now need addition explained to you...

 

[swright777]

If you claim I'm wrong, prove I'm wrong.

You have refused to point out a statement of mine and explain why it is wrong. Instead, you attack me globally and ask me to answer your questions. I will not do this. If you claim I'm wrong, show why I am wrong. Please provide a link to a credible source that shows exactly which statement or concept is wrong.

If I don't understand something, then show me what I don't understand. Stop making claims without proof.

I'll do you a favor. Here is a link to a credible source that shows that your post #317 is wrong.

 

[Dave Rogers]

If you claim I'm wrong, prove I'm wrong.

You have refused to point out a statement of mine and explain why it is wrong. Instead, you attack me globally and ask me to answer your questions. I will not do this. If you claim I'm wrong, show why I am wrong. Please provide a link to a credible source that shows exactly which statement or concept is wrong.

If I don't understand something, then show me what I don't understand. Stop making claims without proof.

In the face of your determination to remain ignorant, any such effort seems futile. I've asked you some questions in the hope that, in working out how to answer them, you might work out for yourself where you're going wrong, because learning things for yourself is far better than simply being told them. But you refuse to even try to learn because you think you know everything already.

One last try. The statement you have made that is wrong is:

Your prediction is not right. There will be an instantaneous deceleration at the instant of impact. There has to be.

This is wrong because forces on the falling object may be added and/or subtracted to produce a resultant force, and it is the magnitude and direction of this resultant force that produces acceleration or deceleration. An object falling under gravity experiences a downward force of mg. If it collides with an object that is only capable of exerting an upward force of mg/2, then the two forces produce a resultant downward force of (mg-mg/2)=mg/2. The object does not therefore decelerate at any point because there is still a downward resultant force acting on it.

I would suggest you read the Wikipedia pages on Force and on Euclidian Vectors, and try to understand how forces add and subtract. When you've done that, you may start to see what you've got wrong. But really, this is almost as absurd as demanding a credible source that confirms that 2+2=4.

Dave

 

[Dave Rogers]

Your post is word salad[...]

You said that about one of my posts too. Have you considered the possibility that there's a different reason why you don't understand what anyone's saying?

Dave

 

[Dave Rogers]

I'll be watching with respectful admiration as you continue to convince reasonably intelligent people that you now need addition explained to you...

Damn it, he got me again. I hate you.

Dave

 

[FalseFlag]

My undergraduate degree was in physics,

Do I need to point out the problems with your post, or will you just accept that you are wrong?

Will you accept post #317 as proof you are wrong, or do I need to dissect each of your claims and prove why they are wrong?

If you ask to me to prove that you are wrong, once I do so by providing reasons and links to credible sources that support my claims, what will I get in return? If you are just going to say that I'm wrong, like the other skeptics do, then I'm not going to waste my time pointing out the mistakes.

 

[Belz...]

If you're trying to make a point, why don't you just make it?

But will you accept it?

If you claim I'm wrong, prove I'm wrong.

You have refused to point out a statement of mine and explain why it is wrong. Instead, you attack me globally and ask me to answer your questions. I will not do this. If you claim I'm wrong, show why I am wrong. Please provide a link to a credible source that shows exactly which statement or concept is wrong.

If I don't understand something, then show me what I don't understand. Stop making claims without proof.

Called it.

 

[Belz...]

Give him a bit of credit, he is learning, just slowly.

No, he's not:

Show me an experiment that proves Cole is wrong. If you can't do that, your post is meaningless.

How many times have we told him that this requirement is nonsensical and ridiculous?

 

[Dave Rogers]

Will you accept post #317 as proof you are wrong, or do I need to dissect each of your claims and prove why they are wrong?

Please post a link to a credible source that demonstrates that post #317 is correct. Sites that give a general explanation of physical concepts are unacceptable; your source must specifically confirm all you state in post #317. Stop making claims without proof.

Dave