Where does a Newton come from?

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In summary: I know. he seems to be the kind of engineer that would just take a hammer, or grinder to something that dosn't work though, lolWell, all of the macroscopic forces human beings feel in every day life are the result of a single fundamental force: electromagnetism. We can quantify and analyze and describe this force to any level of detail you desire. We cannot now (or perhaps ever) explain why the universe includes this force. Physicists don't generally spend much time on these "why" questions, since we cannot answer them. You can always punt and just use the anthropic principle: if the universe were any other way, we wouldn't be here to discuss it.
  • #1
bazz89
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Hey, I'm new to this forums so I hope I'v posted this in the right section.

I'v just started my new job at a large engineering firm, and the chairman has posed a question to all his employee's which I was hoping you could help me with. His Question is as follow;

"Where does a Newton come from and where does it go?"

For example, If I were to hit someone with a force of 1 Newton, where did that netwon come from, and where did it go?

I don't think there is any definitive answer, but i would greatly appreciate your theories and input, cheers.
 
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  • #2
Uhh...It came from your hand and went into whoever you hit?? Is this what your looking for, or something much more in depth. This is really a vague question.
 
  • #3
Yeah, more in depth, sorry should have explained that. I was just using the punch as an example. He is wanting to know where Newtons originate from, and where they go when they have been used.
 
  • #4
bazz89 said:
Yeah, more in depth, sorry should have explained that. I was just using the punch as an example. He is wanting to know where Newtons originate from, and where they go when they have been used.

This question makes no sense. A Newton is a unit of force, not a physical entity that appears and disappears.
 
  • #5
Ok let me try to explain it again, i know its not a very clear question,

He tells us that engineering is all about controling Newtons, he is very obssesed with Newtons, he is trying to figure out where forces originated form, where forces first came to be, my answer was the big bang, but he is asking where they were before the big band? The force needed to create the big bang, where did this force come from? Does anybody have any ideas on pre-big bang in relation to forces?
 
  • #6
bazz89 said:
Ok let me try to explain it again, i know its not a very clear question,
He tells us that engineering is all about controling Newtons, he is very obssesed with Newtons,

That's not how I would put it, but ok...

bazz89 said:
he is trying to figure out where forces originated form, where forces first came to be,

When you think about it, most of the forces encountered in engineering and everday life (e.g. contact forces) are electrostatic in nature. So the question of the origin of these forces is really the question(s)

what is electric charge?
why is matter the way it is?
or even, why is the universe the way it is?

The latest physical theories can put forward models of matter that explain its observed properties, but physics doesn't really attempt to answer why it is so. This is getting into the realm of the philosophical, so I'm not sure why the chairman of your *engineering* company is dwelling on this point.

bazz89 said:
my answer was the big bang, but he is asking where they were before the big band?

I'm no cosmologist, but I think that the statement "before the big bang" is meaningless. Then again, my answer to his question would have been what I said just above, and not, "the forces came from the big bang."
 
  • #7
A Newton, or amount of force if you like, measures the rate of energy transfer.

Thus, it is energy that gets shuffled back and forth, not forces as such.
 
  • #8
ok thanks for your help, i'll see what he says on the matter
 
  • #9
arildno said:
A Newton, or amount of force if you like, measures the rate of energy transfer.

Thus, it is energy that gets shuffled back and forth, not forces as such.

I thought it measured the rate of momentum transfer?

Even so, you make a good point!
 
  • #10
Oh, dear. I am chagrined, embarassed, I shudder with shame and horror and self-loathing. It measures the rate of momentum transfer.

Now, I will go the bucket of water.
 
  • #11
I'm rather embarrassed that any engineer, much less the owner of an engineering firm, would be publicly asking questions as meaningless and ill-formed as this one.

- Warren
 
  • #12
yeah, i know. he seems to be the kind of engineer that would just take a hammer, or grinder to something that dosn't work though, lol
 
  • #13
Well, all of the macroscopic forces human beings feel in every day life are the result of a single fundamental force: electromagnetism. We can quantify and analyze and describe this force to any level of detail you desire. We cannot now (or perhaps ever) explain why the universe includes this force. Physicists don't generally spend much time on these "why" questions, since we cannot answer them. You can always punt and just use the anthropic principle: if the universe were any other way, we wouldn't be here to discuss it.

- Warren
 
  • #14
chroot said:
I'm rather embarrassed that any engineer, much less the owner of an engineering firm, would be publicly asking questions as meaningless and ill-formed as this one.

- Warren
Yeah, I was just thinking - we're supposed to say that there's no such thing as a stupid question, but jeez, this one is pretty bad.
 
  • #15
I want to believe that this chairman isn't an engineer, just because of this question.:cry:
 
  • #16
yeah he used to be, ever heard of Score? its a firm that overhauls and repairs offshore oil and gas valves, they have also branched into overhauling gas generator turbines. he must be doing something right cause he staretd the company on his own about 25 years ago, now its worldwide and he's a multi-millionaire.
 
  • #17
chroot said:
Well, all of the macroscopic forces human beings feel in every day life are the result of a single fundamental force: electromagnetism. ...
You would not include gravity as a macroscopic force human beings feel in every day? Just curious...
 
  • #18
nrqed said:
You would not include gravity as a macroscopic force human beings feel in every day? Just curious...

:rofl: Okay, true. I was thinking only in terms of people punching each other, but of course, you're right.

- Warren
 
  • #19
Since a Newton is a force, it's not directly related to work or energy. You can apply a force (or a torque) without movement, so no work or change in energy occurs.

In the case of a force without movement, it's not going anywhere, it's not getting consumed, ... For example, a compressed spring in a vice. It takes work to initially compress the spring from a relaxed state, but once the movement stops, the spring and vice continue to apply forces to each other, but no work is being done, and no force is being consumed.
 
  • #20
nrqed said:
You would not include gravity as a macroscopic force human beings feel in every day? Just curious...
Well, what you "feel" of gravity is the floor pushing up on you and keeping you from falling through the earth, so it's still electrostatic repulsion.
 
  • #21
russ_watters said:
Well, what you "feel" of gravity is the floor pushing up on you and keeping you from falling through the earth, so it's still electrostatic repulsion.

Yeah, but there are other ways to feel gravity in everyday life (like *falling* for example). I think nrqed's point that it should be included in the category of "forces experienced by humans on a macroscopic scale" is perfectly valid.
 
  • #22
Do you feel gravity if you are falling...?
 
  • #23
russ_watters said:
Do you feel gravity if you are falling...?

Maybe not, but is it necessary to belabour this point when you know what I am trying to say? Unless it is your contention that gravity can never be felt in everyday life. What about when you are struggling to try to keep your balance? What about when you fail to do so, because your centre of gravity shifts in an unexpected way?
 
  • #24
bazz89 said:
Hey, I'm new to this forums so I hope I'v posted this in the right section.

I'v just started my new job at a large engineering firm, and the chairman has posed a question to all his employee's which I was hoping you could help me with. His Question is as follow;

"Where does a Newton come from and where does it go?"

For example, If I were to hit someone with a force of 1 Newton, where did that netwon come from, and where did it go?

I don't think there is any definitive answer, but i would greatly appreciate your theories and input, cheers.

Let me give it a try. Remember a Newton as a force is a rate of change of momentum. It is the momentum (Newton-seconds=kg meters/sec) which is conserved (and thus must "come from somewhere" and "go somewhere").

You could in principle slap me with a million Newtons but do it so quickly (for one quadrillionth of a second) that only one one-millionth of a Newton-second is imparted to my face.
I wouldn't feel a thing.

Until you specify how long a period of time a Newton is applied then nothing has been defined to have happened.

Usually when you see idealized impulsive forces which cause instantaneous changes in the path of a massive object the force (number of Newtons) is formally infinite since the duration is infinitesimally small so that the impulse (change in momentum) is finite. This is an idealization where we don't care exactly how long the actual force was applied as long as it was only large for a short period of time.

This is also relates to the principle behind airbags, padded helmets, and other impact cushioning devices. They stretch out the time it takes for the user's momentum to change from whatever to zero. Thus they reduce the maximum force applied and keep bones from breaking and flesh from bruising (too much).

Regards,
James Baugh
 
  • #25
I suppose we would need to differentiate between statics and dynamics.

Perhaps this guy is testing his engineers to see how they respond to questions, or perhaps he is waxing philosophical.

I would hope any engineer has some basic notion of where force arises.
 
  • #26
russ_watters said:
Well, what you "feel" of gravity is the floor pushing up on you and keeping you from falling through the earth, so it's still electrostatic repulsion.

Yes, you are right. I agree that, given that GR is the correct theory of gravity, we do not experience any effect of gravity in our daily lives (setting aside the tides!). So you made a very good point.
However, I am of the opinion that teaching involves as much choosing what to leave *out* as choosing what to explain. In the context of someone wanting to discuss something about very basic notions of forces in classical mechanics, I would tend to leave the whole spacetime curvature business out of the discussion and treat gravity in the Newtonian context.
I mean, if someone in this thread uses [itex] \sum \vec{F} = m \vec{a} [/itex] or even the more correct [itex] \sum \vec{F} = \frac{d \vec{p}}{dt}[/itex] would you correct them by saying that they should be using the full covariant equation including covariant derivatives and tensor notation?

Thanks for your interesting point, though!

Regards

Patrick
 
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  • #27
jambaugh said:
Let me give it a try. Remember a Newton as a force is a rate of change of momentum. It is the momentum (Newton-seconds=kg meters/sec) which is conserved (and thus must "come from somewhere" and "go somewhere").

You could in principle slap me with a million Newtons but do it so quickly (for one quadrillionth of a second) that only one one-millionth of a Newton-second is imparted to my face.
I wouldn't feel a thing.

Until you specify how long a period of time a Newton is applied then nothing has been defined to have happened.

Usually when you see idealized impulsive forces which cause instantaneous changes in the path of a massive object the force (number of Newtons) is formally infinite since the duration is infinitesimally small so that the impulse (change in momentum) is finite. This is an idealization where we don't care exactly how long the actual force was applied as long as it was only large for a short period of time.

This is also relates to the principle behind airbags, padded helmets, and other impact cushioning devices. They stretch out the time it takes for the user's momentum to change from whatever to zero. Thus they reduce the maximum force applied and keep bones from breaking and flesh from bruising (too much).

Regards,
James Baugh

This is a very interesting way to introduce forces, as long as one emphasizes that it applies only to the *net* force. Of course, in many simple examples that one presents to students, there is no change of momentum at all and yet it is still useful to discuss the forces involved, even though they add up to zero (like holding the extremity of a stretched string, sitting on a chair, and so on). So I think that although this is a very useful way to discuss the net force on objects, one must also discuss individual forces and their meaning even when each force by itself cannot be explained in terms of change of momentum.
 
  • #28
Perhaps your boss should be asking questions to the company like, how can we improve our product to increase profits and customer needs?

What a stupid question that wastes peoples time when they should be working. :confused:
 
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  • #29
If it were me, I'd sneak in a bag of fig Newtons into the bosses in box, with a note that this is where Newtons come from.
 
  • #30
nrqed said:
This is a very interesting way to introduce forces, as long as one emphasizes that it applies only to the *net* force. Of course, in many simple examples that one presents to students, there is no change of momentum at all and yet it is still useful to discuss the forces involved, even though they add up to zero (like holding the extremity of a stretched string, sitting on a chair, and so on). So I think that although this is a very useful way to discuss the net force on objects, one must also discuss individual forces and their meaning even when each force by itself cannot be explained in terms of change of momentum.

Ah, yes. I wasn't thinking in terms of statics problems. It would be easy to segue into statics as the case where no momentum is transferred over arbitrary time. (And all momenta are initially zero).

It may not be the best way to sequence the concepts for introductory instruction but I think an improvement when used to summarize cases after the introductory sequence.

Regards,
James
 

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