Simply I want to know;-
Whether measurable thermodynamic changes occur in any substance(atoms
also) on variations in its potential energy? Increase or decrease in
applied Gravitational force on any substance should change that
substance in some manner.
Best wishes.
In other sense, can we measure variations in potential energy of any
substance by its heat & motion(thermodynamic) or by it thermodynamic
variations ?
Yes - take a look at how the sun works.
It's own gravitational pull is enough to cause high pressures and
temperatures at the center - enough to cause the fusion of hydrogen atoms.
Thanks. If we put a ball high on hill. Will it get change in
gravitational force & will it change its thermodynamics?
You do work on the ball giving it potential energy (PE) in a gravitational
field. Upon release PE is converted to kinetic energy (KE). The ball's
KE is dissipated, often in the form of heat.
May I suggest you read: http://www.motionmountain.net/index.html
But if there are variation in applied GF on hill, will it not cause
persistent thermodynamic changes in ball? Suppose GF is decreased on
hill, it can lower motions in ball due to decrease in applied forces &
till ball is on hill, these motions will be persistent. Then how these
motions are not considered in arriving at PE?
>>
>> You do work on the ball giving it potential energy (PE) in a gravitational
>> field. Upon release PE is converted to kinetic energy (KE). The ball's
>> KE is dissipated, often in the form of heat.
>
> But if there are variation in applied GF on hill, will it not cause
> persistent thermodynamic changes in ball? Suppose GF is decreased on
> hill, it can lower motions in ball due to decrease in applied forces&
> till ball is on hill, these motions will be persistent. Then how these
> motions are not considered in arriving at PE?
What kind of variations are you envisioning? The mass of the earth is
essentially constant, therefore the acceleration due to gravity is
essentially constant.
You can calculate the difference in PE for the height of the hill from
newton law of gravitation
∆g = mG / ∆r^2
where ∆r is the difference to the center of mass of the earth from
to top and bottom of the hill.
A Physics Booklist: Recommendations from the Net
http://math.ucr.edu/home/baez/physics/Administrivia/booklist.html#general-physics
I mean to say you can calculate the the difference in g (not PE).
Then, what is the importance of h(height) in mgh?
Ug(PE)=mgh. In it, whether height is not important to calculate both
gravity & PE? Will it not suggest that height can vary GF?
You can calculate the difference in aceleration due to gravity as a
function r
It means, there will be variation in gravity at bottom & top on the
hill ans there will also be some difference in aceleration in a
substance due to gravity variation?
>Then, what is the importance of h(height) in mgh?
mgh is the objects _potential_ energy.
It comes from
work = force x distance
force = mass x acceleration
It can't be converted to another form without changing h.
I don't think there is a way to convert potential energy to another form by
somehow changing g or m.
And they are negligible to at least six (6) decimal places. You
are not likely to have input data better than thre (3) decimal
places.
The field /is/ where elèctròns or other matter are.
Likewise, will there be variation in weight of substance at bottom &
top on the hill?
On Gravity push, it was told that EM forces resist us in going down,
can it be possible that there can be a push but other forces esp. EM
resist it?
Does it mean that mass which is also a consolidation of energy & can
be converted into energy do not come under the preview of potential
energy? Do you mean that PE is something which is in energy form not
in matter/mass form?
> The concept of temperature was originally tied up with the idea of
> a "temperature force field." The "internal energy" of an object is an
> analog to potential energy. The entropy of the object, sometimes
> called the caloric, was considered a type of fluid. The "temperature
> gradient" was actually the analog to a force field. Originally, Carnot
> thought of the working of a steam engine as being like the working of
> a water mill. The major difference, where the analogy completely
Wecome & thanks.
Do you meant PE is represented by permanent or stable temp. of a
substance which can be generated by internal energy which is in
motion?
> breaks down, is that entropy can be made in an irreversible process.
> In any case, you can't a priori assume that one form of potential
> energy (including internal energy!) automatically affects a substance
> the same way as other forms of potential energy. To see how these
> different forms of energy interact, you need an equation of state
Can diffrent type of PE be commonly related to the variations in heat
(temp.) & motions of a substance?
.>Increase or decrease in
> > applied Gravitational force on any substance should change that
> > substance in some manner.
>
> This is what I mean. Gravitational potential energy doesn't
> change the chemical nature of a material. You are thinking of chemical
> potential energy.
> If someone jumps off a cliff, the change in gravitational
> potential energy won't change the chemicals in his body. When he hits
> the ground, he will change the amount of elastic energy in the bones
> of his body. This still won't change his chemistry very much. When his
> bones break and his organs rupture, there will be an increase of
> entropy in his body. This will change his chemistry immensely. He will
> be dead.
Chemical changes is anoher thing. Here, I am trying to understand
measurable variations in heat(temp.) & motions?
Can we consider temp. of a substance, esp. persistant, is relevant to
PE whereas its radiated heat to KE?
This was a confusion to me also. Whether field is not dependant on
electrons & matter?
Will you tell more about it?
> Do you meant PE is represented by permanent or stable temp. of a
> substance which can be generated by internal energy which is in
> motion?
How many ways can I say no before you understand me?
Sorry, although you tried but it is bit difficult fore me. Let us take
three thinhs. One is matter, 2nd permanent motions in a substance, 3rd
current motions due to applied forcs. As matter has potential to be
converted into energy. Permanent motions in a substance(eg in atoms)
(i don't know it is potential or KE), current motions should be KE.
Now pls tell accordingly.
Sorry, Whether confriguration changes don't cause changes in an atom?
Sorry. I don't understand your question at all. I tried to
understand, but I can't.
PE is related as a result of change in position &
confriguration.Whether Such change in confriguration don't cause
changes in relevant atoms? Eg. on chemical bonding, some changes occur
in atoms.
and of flux and effluvium?
> I will use as an example electromagnetic energy. An electron is
> usually thought of as "matter." If it moves, it has kinetic energy
When is it not?
> [KE=0.5mv^2]. However, the electron is not the electric field or the
> magnetic field.
No, but it's at the field.
> However, attached to the electron is the electric field. The
> electric field lines are conventionally shown with arrows moving into
> the negative charge (here the electrons). They extend outside of the
> electron. They push and pull other particles of "matter" outside the
> electron. If the electron moves, it has magnetic field lines arranged
> in circles around it. The magnetic field lines don't touch the
> electron at all.
Your model is classic, popular, and wrong. There is no outside of the
elèctròn other than outside of its univers. The [free] elèctròn has a
inner size (classic elèctròn radius) and outter size (causal horizon
radius); its field and body are coincident: http://google.com/groups?q=Autymn+-autumn+sun+bird.
> If the electron oscillates, electromagnetic waves travel down the
> field lines. These waves act independently of the electron that
> generated them. You could say in the case of the light (radio, xray,
> gamma ray) that it consists of oscillating electric fields and
> magnetic fields that act independently of electrons.
ocsýmòròn. Well, there's a far-field and near-field, and hýsteresis.
> This is why physicists in all their calculations distinguish
> between "currrents" and "fields." The currents represent the motion of
> what is called "matter" and the fields represent the direction of the
> "fields."
matter (- field; 's`(matter) = <'field'>
> I used to get confused in problems when I thought of the
> potential energy as being contained in the falling object itself. It
> helps me keep things straight to think of the potential energy as
> being contained in the field. The PE may be said to belong to the
> particle falling, but the PE is located in the field. So to me, the
> field is like a bank. It contains the energy that properly belongs to
> the particles. I throw this picture away when I get to the really
> advanced problems, however |:-)
yawn
-Aut
Upon a bond, PE lowers, enthalpy lowers, and entropy rises.
Pls tell me more about enthalpy lowers & entrophy rises? Is there any
change at global/unversal level due to any bond?
> Pls tell me more about enthalpy lowers & entrophy rises? Is there any
> change at global/unversal level due to any bond?
The global/universal level of what?
This is one of the problems understanding your question. You have
a jargon that may come from another subject which the rest of us
don't understand.
On any change in local temp. whether some changes also occur in
thermodynamic equilibrium of universe?
In thermodynamics, the metric for thermodynamic equilibrium is the
amount of entropy. The conventional theory is that the global entropy
has to increase, it can never decrease. The conventional theory says
that it will increase until it can't increase anymore.
However, the local entropy density can decrease. This is a
confusion some nonscientists have. A particular reaction can decrease
the entropy density in a confined region of space. However, when adds
up all the entropy in a closed system, the entropy must decrease.
An example would be when a plant grows. The entropy density in
the volume of the plant decreases as it grows. However, the total
entropy increases due to the growth of the plant.
It is as though the plant is pumping entropy into its
surroundings. It's chemical reactions suck out the entropy in the
material that makes the plant, and spreads it around. In addition, the
chemical processes of the plant manufacture lots and lots of entropy.
Same thing as the organism grows, reproduces, and evolves.
Same thing for a refrigorator. The chamical and physical processes
in the refrigorator lower the entropy density inside the refrigerator.
Entropy is sucked out of the refrigerator. That is why ice forms in
the ice trays of the refrigorater. However, the refrigerator doesn't
reduce the global entropy. It creates even more. A refrigorater
actually heats the surrounding area.
Thanks. I think global warming is a similar example.
entrophy is defined as; "randomness, entropy, S ((thermodynamics) a
thermodynamic quantity representing the amount of energy in a system
that is no longer available for doing mechanical work) "entropy
increases as matter and energy in the universe degrade to an ultimate
state of inert uniformity"
What does it mean by matter and energy degrade to an ultimate state of
inert unfiformity? What is inert uniformity & how energy can degrade?
> However, the local entropy density can decrease. This is a
> confusion some nonscientists have. A particular reaction can decrease
> the entropy density in a confined region of space. However, when adds
> up all the entropy in a closed system, the entropy must decrease.
Thermodýnamics say otherwise--entropy lowers in a open sýstem--but
screw arbitrary frames. Elèctronics still believe holes drive
currend.
> An example would be when a plant grows. The entropy density in
> the volume of the plant decreases as it grows. However, the total
> entropy increases due to the growth of the plant.
Ayye, in growth many other molecula are implicate as intermediate
states and blow up the population as they were in the ground and loft
when the seed and sun weren't there.
-Aut
It will if you include gravitational time dilation under
"thermodynamic properties"! Otherwise, no (in a uniform gravitational
field -- tidal stresses and local changes in g change the answer
somewhat).