Part 4. newton & kung fu

© ABCC Australia 2015 www.new-physics.com

SECOND LAWNewton’s


Newton’s Second Law

Acceleration motion is described by Newton’s Second Law, which says:When a particle is acted on by an external force, it accelerates. The acceleration is proportional to the magnitude of the applied force 𝑭𝑭 and is in the same direction as the applied force. If the particle has a mass 𝑚𝑚 and the applied force is represented by the vector 𝑭𝑭, then: 𝑭𝑭 = 𝑚𝑚𝒂𝒂.

State of rest Object accelerated to 𝑣𝑣Force Applied


Constant Force and Motion

As we have said the action of changing the state of motion of an object is tantamount to the application of force on the object. When a force is applied horizontally to an object resting on a frictionless surface, the object moves and attains a certain speed. Aristotle fully recognized that this force is the cause of motion. However, he did not know about friction working on the object. Thus he came to the observation that a constant supply of force is required to keep the object in motion.


Constantly Adding Force = Acceleration

In Galileo’s and Newton’s theory, if force is applied to an object constantly, there is constant increase in momentum and thus resulted in constatnt acceleration.

Acceleration


Investigations on Force

But this ‘force’ which is so central to Newton’s theory of motion, was not clearly explained by Newton himself. It seems to be a kind of action causing agent which exists mysteriously in nature which he did not explain at all. People worked hard for thousands of years trying to find what it is: pioneer scientists wrote books on it. Notable examples are ‘Concepts of Force’ (1957) by Max Jammer (1915-2010) and ‘Forces and Fields’ (1965) by Mary Hesse (born 1924).

Hundreds of other scientists also talk about it in thesis, papers and textbooks. But none can give us a satisfactory answer to the nature of force.


Momentum Change

Fortunately, in Newton’s theory, there is another definition of acceleration and force. This is the change in momentum 𝑝𝑝. Remember that acceleration is but the time change in velocity, that is:

𝑎𝑎 =𝑑𝑑𝑣𝑣𝑑𝑑𝑑𝑑

If 𝐹𝐹 = 𝑚𝑚𝑎𝑎, then:

𝐹𝐹 = 𝑚𝑚𝑎𝑎 = 𝑚𝑚𝑑𝑑𝑣𝑣𝑑𝑑𝑑𝑑

Which ends up as:

𝐹𝐹 = 𝑚𝑚𝑎𝑎 = 𝑚𝑚𝑑𝑑𝑣𝑣𝑑𝑑𝑑𝑑 =

𝑑𝑑𝑚𝑚𝑣𝑣𝑑𝑑𝑑𝑑

𝑚𝑚𝑣𝑣 is the momentum 𝑝𝑝 of the system. So we have:

𝐹𝐹 =𝑑𝑑𝑝𝑝𝑑𝑑𝑑𝑑

𝑭𝑭𝑭𝑭𝑭𝑭𝑭𝑭𝑭𝑭

=

𝑪𝑪𝑪𝑪𝒂𝒂𝑪𝑪𝑪𝑪𝑭𝑭𝒊𝒊𝑪𝑪

𝒎𝒎𝑭𝑭𝒎𝒎𝑭𝑭𝑪𝑪𝒎𝒎𝒎𝒎𝒎𝒎


Momentum Change

Thus we have a basic nature of force as the change in momentum. This is correct so far in view of the motion of an body by added momentum to it, equivalent to the application of force.

Receiving momentum and moves accordingly

Force Applied = momentum injection


Momentum Changes Motion

Momentum is important not only because it is the agent that choreographs constant rectilinear motion. It is also associated with acceleration and deceleration. When an object is at rests, the addition of momentum will spurs it on to motion; on the other hand, when a travelling object losses momentum, it slows down and drop to a stop.


Momentum & Acceleration

A particle at rest is one without any momentum (known previously as impetus). As said, it is not a special state. It is only a state being without any momentum.

Particle B at restWith velocity v = 𝑣𝑣𝐵𝐵 = 0The state being without momentum

Palm not moving, thus no momentum


Mechanism of Acceleration

The particle being stricken gets the momentum from the palm and move away with the momentum.

Particle B in motionWith velocity 𝑣𝑣 = 𝑣𝑣𝐵𝐵Momentum is doing all the work. The particle now is a free one.

Palm gathering momentum for a push.

Particle being push thus gaining momentum from the palm and starts to accelerate.

Momentum enters body of particle

Particle at rest❶ ❷ ❸


Adding Force = Acceleration

We can also see that momentum is transferred only when objects are in contact. If we can extend the space of contact as a large zone visible to the eye, we can see momentum happily migrating from the pushing host to the object.

Contact zone


Collisions – When Momenta Change Hands

The transfer of momenta may happen under many situations. But the essence is in the duration of transfer. The momentum will be small when the transfer time in long; and vice versa.

Particle being push thus gaining momentum from the palm and starts to accelerate. The touch is soft.

In collisions, the exchange of momenta is fast and strong’.


Modified Second Law

So we added Part 3 of Law One into Law Two, and change force into momentum at the same time, we have a modified version of Law Two, written as:

𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹 𝑖𝑖𝑖𝑖 𝑑𝑑𝑡𝐹𝐹 𝐹𝐹𝑡𝑎𝑎𝑐𝑐𝑐𝑐𝐹𝐹 𝐹𝐹𝑜𝑜 𝑚𝑚𝐹𝐹𝑚𝑚𝐹𝐹𝑐𝑐𝑑𝑑𝑚𝑚𝑚𝑚 𝑖𝑖𝑐𝑐 𝑑𝑑𝑖𝑖𝑚𝑚𝐹𝐹. 𝐹𝐹𝐹𝐹𝑇𝑇𝑡𝐹𝐹 𝐹𝐹𝑡𝑎𝑎𝑐𝑐𝑐𝑐𝐹𝐹 𝐹𝐹𝑜𝑜 𝑚𝑚𝐹𝐹𝑚𝑚𝐹𝐹𝑐𝑐𝑑𝑑𝑚𝑚𝑚𝑚 𝑖𝑖𝑐𝑐 𝑑𝑑𝑖𝑖𝑚𝑚𝐹𝐹 𝑐𝑐𝑖𝑖𝑣𝑣𝐹𝐹𝑖𝑖 𝐹𝐹𝑖𝑖𝑖𝑖𝐹𝐹 𝑑𝑑𝐹𝐹 𝑜𝑜𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹


Modified Second Law

The resultant corollaries are:i. Acceleration is the result of velocity change:

𝑎𝑎 =𝑑𝑑𝑣𝑣𝑑𝑑𝑑𝑑

ii. Force is the result of momentum change:

𝐹𝐹 = 𝑚𝑚𝑎𝑎 = 𝑚𝑚𝑑𝑑𝑣𝑣𝑑𝑑𝑑𝑑

=𝑑𝑑𝑝𝑝𝑑𝑑𝑑𝑑

iii. The direction of force is related to the direction of the momentum transfer.

FORCE?


Popularity of Force over Momentum

These are the main reasons why momentum is of priority in the consideration of particle collisions. Force is a compound concept which is more convenience for handling mechanical applications. So convenient that the origin of force is overlooked. Laymen are more familiar with the concept of force rather than momentum and will mistake the two as the same.


Momentum the Basic Ingredient.

Force is the manner momentum is transferred. So the basic ingredient of the Second Law of motion is also momentum.


THIRD LAWNewton’s


Newton’s Third Law of Motion

Law No. 3:

Whenever one body exerts a force F onto a second body, the second body exerts the force −F on the first body. F and −F are equal in magnitude and opposite in sense, that is:

𝑭𝑭𝟏𝟏𝟏𝟏 = − 𝑭𝑭𝟏𝟏𝟏𝟏ACTION REACTION


Newton’s Third Law

When we are standing, our body weight is being transferred through our soles onto the floor below us. That we are being kept from falling through the floor is due to the fact that the floor is also exerting a reacting force on our soles. The reaction is exactly equal to our body weight to keep us in place.

Our weight is counteracted by an opposite and equal reacting force or reaction, that is:

𝑭𝑭12 = - 𝑭𝑭21

Weight

Floor reaction

F12

- F21


Force involving Stress

In this law, two opposing forces are involved. The application of force on an objects and the reaction force from the object is a complicated process involving the development of stress in the object. We shall deal with this matter when we come to examining the problem in a more microscopic level. Is suffices here to say that action and reaction is also a fundamental property momentum, the nature of which Newton did not give any further explanation.


MOMENTUM

MOMENTUM

Momentum – Foundation to all 3 Laws

MOMENTUM EXCHANGE


But What is Momentum?

So momentum is the essence of motion.

But what is momentum?

Newton has a formulae for momentum. But he did not explain what momentum actually is.

Is it an imaginary entity? Is it something mathematically abstract? Or it is something solid?

Is what we have found only the tip of an iceberg of theoretical physics?


We have it. But we do not know what it is.

We have got it. But we do not know what it is. Not even Einstein can give us a clue.

May be we should now think out of the box and try to find some hints as to what it is.

Let us go to the Easter world.


FORCE FLOWING OUT OF BODY


Kung Fu

Kung Fu in China is the art or technique of using force effectively for health or to cause harm to one’s opponents. It is often referred to in the West as Chinese martial art.

Chinese martial art had been in existence in China for millennia. All practitioners know how to use force well in thousands of styles. The basic concept is to develop ways to harness one’s innate energy resources and expand it when the need arises. As kung Fu pre-existed the study of physics, the way of Kung Fu is shrouded in mystery.

Picture credit – Wikipedia


Transfer of Energy

The commonest performance of Kung Fu is the generation of energy inside the body and inject it through the leg or fist into the body of an enemy. If the injection is fast and powerful, the body of the enemy cannot adjust fast enough to accommodate the strike, the body parts become deformed and damaged. So force is understood to be the transfer of energy from one body to another.


Chi into Kung Fu

If one can manipulate this Qi well, not only would one become healthier, but the force or power issued from his body will be much greater. So force in the mind of the practitioners became something that can be moved around inside the body or even be ejected from the body to affect your opponent.

In the beginning of the 6th century, the concept and practice of Qigong (the practice of Chi or Qi) was introduced into Kung Fu and the Qi style of Kung Fu emerged. The success led to the believe that force is the manifestation of this mysterious Qi or fluid force inside the body.

Picture Credit : Jade comics. Hong Kong.

© ABCC Australia 2015 www.new-physics.comPicture Credit : Jade comics. Hong Kong.

Force Gone Berserk

This detachable force becomes an essential part of Kung Fu comics, especially those found in Hong Kong and the rest of Asia. The force can be moulded into different forms for any disastrous results.


Explosive Power from Detachable Forces

The forces do not need to be generated and transferred in contact. They can be issued from the body and be seen like firework everywhere around the combatants. The more brilliant and violent they are, the greater would be the power. This is also done to effectively impress the readers so as to exhort the greatest resonance from the readers.

Picture Credit : Jade comics. Hong Kong.


Japanese PowerThe practitioners may sometimes achieve developing telekinesis or psychokinesis. They can gather enough power in their body and issue forward a powerful blast to eliminate their enemies. Of course, if the enemies also know how to do it, they would blast back, and a battle more awesome than cannons and fire ensures.

Picture Credit : Dragon Balls. Japan.


Picture Credit: Capcom. Super Buster Wolf.www.Capcom-unity.com


Metropolitan Destroying Power

When carried to extreme, may end up with city-destroying powers as so popular in many Japanese manga. I saw Akira was described as the man who could summon enough power to destroy the Tokyo city.

Picture Credit : Japanese comics Akira


Western Concepts

The Asians are now not alone. The Westerners are fast catching up. The Star War movies portrait characters with more mysterious power. To the creator of Star War, force seems to be some sort of gas diffused throughout the universe, and warrierswho are properly trained could use it for good or bad purposes.


Contact & Detachable Force

So there are two types of force concepts prevalent in the world culture. One is the contact force that is commonly used in daily life and in combats; the other is the detachable or remotely controlled force popular in comics and fictions.

Contact Forces Detachable Forces


Force in Contact

Presentation of force styles may vary, but the

underlying concept are the same. More or less

the practitioners understand that force is a kind

of substance that can be created and shared. It

may or may not be leaving the body as an

extension, but the fact that its needs for a solid

contact to be transferred cannot be denied.

The same feeling exists in both the East and the

West civilizations. Momentum and Force cannot

be seen, but they are tangible and may be

existing everywhere. They have been there

waiting to be recognized for thousands of years. Force transferred on contact.

Part 4. newton & kung fu

Science

Transcript of Part 4. newton & kung fu