Talk:Newton's laws of motion

poor quality

It's too bad that such an important subject (rated Top-importance by WikiProject physics) is covered by an article that is of such poor quality (rated C-Class). It's clearly not healthy that the page has been protected or semi-protected for such a long time ... since 2008?? The article has some serious problems in terms of readability by the general reader. Some suggestions: (1) Dump the Latin statements from the Principia and their English translations. Give modern statements of the laws. (2) Dump the calculus. The general reader doesn't know calculus.--75.83.69.196 (talk) 02:16, 4 December 2011 (UTC)

The C rating may or may not be earned. But any weakness in this article is NOT due to either the math or latin. Both can easily be skipped over without affecting the readability of the article. The modern formulation of each law are clearly stated. As far as the semi-protection, the article is clearly better than it was before the semi-protection. TStein (talk) 03:49, 4 December 2011 (UTC)

This article is clearly intended for someone with a background in science. It's not readable for the lay audience. — Preceding unsigned comment added by 68.34.138.122 (talk) 23:12, 4 January 2012 (UTC)

Wikipedia should not be a poor encyclopedia, this article has good level

This article is fine with the latin cites and calculus. STOP the intent to convert Wikipedia in an encyclopedic dictionary or a high school level compendium.

If a layperson is searching for this subject that is because (s)he is interested in science. Moreover, (s)he can learn that differential calculus was the language that allowed to express those laws, differential calculus allow us to express the dynamics of the world.

Wikipedia articles should have a deep insight on each subject.

I agree to have this page protected to prevent unjustified simplification.

Maybe it is time to open a new wiki site, wikicompendium addressed to a high school audience, more similar to an encyclopedic dictionary, or an illustrated dictionary. I have stop to write in wikipedia, because of vandals that erase what I write because they want to oversimplify the content or because they write wrong concepts because they do not know the subject more than is tough in high school.

See other encyclopedias, the old ones printed in paper, to see if they are as simple as some people want to destroy this important effort to have a place to consult all the known to humanity. — Preceding unsigned comment added by 189.140.229.42 (talk) 06:22, 27 July 2012 (UTC)

figure skaters and 3rd law

hi, I wonder if the figure skater diagram is optimal? It doesn't indicate any forces: are they holding hands while spinning? are they (about) to push apart? Are there any forces at all involved?

Also, the key 3rd law concept is that of opposite laws: An ideal diagram would show one person pushing the other, and experiencing a force back into their body (the opposite reaction, and also the correct image for a free body diagram...

Newton's Third law and the Buddhism

Buddha says that every action has its own fruit and the doer must receive the fruit of what he has done. Action and reaction. - Pali Canon it's obviously mentioned by Lord Buddha first ,the credits should be gone to the Lord Buddha not Newton for this universal law. — Preceding unsigned comment added by Faulknerck2 (talk • contribs) 13:38, 12 February 2012 (UTC) oh golly you know you have to have the motion included with this there nothing up here that has to do with why he was able to figure this stuff out. — Preceding unsigned comment added by 24.171.168.127 (talk) 17:28, 23 May 2012 (UTC)

Removal

I removed the following as the conservation of energy article disproves it: Conservation of energy was discovered nearly two centuries after Newton's lifetime, the long delay occurring because of the difficulty in understanding the role of microscopic and invisible forms of energy such as heat and infra-red light.

Edit request on 29 August 2012 (Second Law)

Replace the follwing:

where, since the law is valid only for constant-mass systems, the mass can be taken outside the differentiation operator by the constant factor rule in differentiation. Thus,

With:

if the system's mass is constant, mass can be taken outside the differentiation operator by the constant factor rule in differentiation. Thus for constant mass,

Reason:

The claims that mass must remain constant are incorrect as that does not apply to rockets which are described by Newton's second law in it's momentum form. In fact, Newton's second law in momentum form is used with variable mass to prove the Tsiolkovsky rocket equation. 184.99.251.11 (talk) 23:30, 29 August 2012 (UTC)

If you assume a time-varying mass and then apply the product rule to Newton's second law $F=d(mV)/dt$ to a rocket of mass $m(t)$ and velocity $V(t)$, you will end up with

$F=m{\frac {dV}{dt}}+V{\frac {dm}{dt}}.$

Compare this to the equation used to derive the Tsiolkovsky equation:

$F=m{\frac {dV}{dt}}+(V-V_{\mathrm {e} }){\frac {dm}{dt}}.$

The two equations are evidently not the same; the latter includes an extra term involving the exhaust velocity. If you attempt to use Newton's second law + product rule to derive the behavior of a rocket you will get the wrong answer. Zueignung (talk) 01:22, 30 August 2012 (UTC)

 Not done: as per Zuenignung.

Italicse Principia Mathematica in caption

The words "Principia Mathematica" should probably be italicised in the figure caption in the lead section. 203.176.108.99 (talk) 04:39, 31 August 2012 (UTC)

Fixed. Good catch. Zueignung (talk) 04:48, 31 August 2012 (UTC)

Newton's First Law Of Motion Needs a Refinement

It has been pointed out by Hasmukh K. Tank, (Ref: www.physforum.com, New Theories, A refinement of Newton's First Law of Motion), that: since every object has some 'mass' and 'energy', there is always a 'gravitational-potential-well' around it; so when it tries to move in any direction, it has to 'climb' its own 'gravitational-potential-well', so it experiences a constant deceleration. Decelerations experienced by the Pioneer-10, Pioneer-11, Galileo and Ulysses space-probes, of the order of 10^-10 meter per seconds-square were beceuse of this, due to their own 'gravitational-potential-well'. Even the linear-part of 'cosmological-red-shift', is because of the photon's own 'gravitational-potential-well'. Receeding galaxies too experience this deceleration, because, it is shown that: the globular-clusters, the spiral-galaxies, and the galactic-clusters, have self-gravitational-deceleration at their "surfaces" of the value equal to the decelerations of the four space-probes and the inter-galactic-photons.49.213.52.32 (talk) 11:45, 4 September 2012 (UTC) th — Preceding unsigned comment added by 14.96.165.21 (talk) 08:49, 9 September 2012 (UTC)

There is nothing there to discuss. That is not a peer reviewed paper reflecting any form of scientific consensus or even legitimate diverging opinion - it is a user post to a bulletin board and has already been debunked there. To that debunking I will add that if true this would break the law of conservation of momentum, the law of conservation of energy, and imply the existence of a frame of absolute rest. Those are pretty big barriers to overcome that any legitimate theory would need to convincingly address. It doesn't touch upon them in the slightest. This is no different to any of countless other self-published scientific "revelations" written without a basic grounding in the subject matter at hand that are nothing more than a waste of everyone's time. Crispmuncher (talk) 18:55, 9 September 2012 (UTC).

Newton's Third Law Can't Be This Terrible... Can it?

The current version on the article states the following: "Third law: When two bodies interact by exerting force on each other, these forces (termed the action and the reaction) are equal in magnitude, but opposite in direction."

In otherwords this is saying "When 2 bodies are exerting ANY force on each other even if they're different, these forces are equal yet opposite". Either Newton was an idiot or someone made a grave error. Zoele (talk) 21:05, 9 September 2012 (UTC)

I changed it. Better, or still unclear? Zueignung (talk) 21:51, 9 September 2012 (UTC)

I think the OP was challenging the theory, not the notation - "When 2 bodies are exerting ANY force on each other even if they're different" implies a grave error indeed, but on on the part of the asker - the two forces are always the same which is the crux of the third law. Using mathematical notation in place of prose in text like that does not strike me as being an improvement. Crispmuncher (talk) 05:42, 10 September 2012 (UTC).