Questions about Forces?
Kumar
I am trying to find awnsers to following questions:-
1. Suppose if we make a straight hole through the earth from one end
to other, seal hole with a pipe & put one stick in it, will it pass
through the earth or not?
2. Which type of potential energy is related to which fundamental
force? Eg. gravitational potential force to gravity.
3. When a ball hit the ground it came back. Is it a repulsion or push
from earth?
In a simple experiment, I put a small object in a glass bottle,
vacumed it by pulling air from mouth & then I reversed bottle
position. As that object also moved & came to mouth side from bottom,
is it sufficient to tell, gravity is not a centrpetal force due to its
revolution or a tornado effect or an atmospheric pressure pushing an
object down to earth surface?
Best regards.
Sam Wormley
>
> 1. Suppose if we make a straight hole through the earth from one end
> to other, seal hole with a pipe& put one stick in it, will it pass
> through the earth or not?
Assuming no frictional or magnetic resistances and the "hole"
along the earth's axis of rotation, one would expect an object
dropped in to reach the same height from the center of earth's
mass on the other side.
Start with the differential equation F = dp/dt
Javi
> Hello,
>
> I am trying to find awnsers to following questions:-
>
> 1. Suppose if we make a straight hole through the earth from one end
> to other, seal hole with a pipe & put one stick in it, will it pass
> through the earth or not?
If you ignore friction, it would oscilate around the center of gravity of
the earth. The amplitude would have an amplitude of the earth diameter. If
you consider the air friction, the oscillation would be amortiguated until
it stops at the center of the Earth.
>
> 2. Which type of potential energy is related to which fundamental
> force? Eg. gravitational potential force to gravity.
>
Gravitational, as you say.
> 3. When a ball hit the ground it came back. Is it a repulsion or push
> from earth?
>
No, it's attraction to the center of the earth.
> In a simple experiment, I put a small object in a glass bottle,
> vacumed it by pulling air from mouth & then I reversed bottle
> position. As that object also moved & came to mouth side from bottom,
> is it sufficient to tell, gravity is not a centrpetal force due to its
> revolution or a tornado effect or an atmospheric pressure pushing an
> object down to earth surface?
>
I didn't really understand your reasoning. Gravity is a centripetal force.
Tornado, anticyclones, etc twist because of the Coriolis force (an imaginary
force needed because we aren't in an inertial reference system):
http://en.wikipedia.org/wiki/Coriolis_effect
> Best regards.
Kumar
Thanks. How center of earth is important in gravity?
Sam Wormley
Gravitation decreases on the way to the center, but velocity
is increase all the way to the center reaching v_max at the
earth's center.
Kumar
>
> - Show quoted text -
Whether velocity is not related to gravity? Should velocity not
decrease due to decrease in gravitation?
Greg Neill
>
> Whether velocity is not related to gravity? Should velocity not
> decrease due to decrease in gravitation?
Learn the difference between acceleration and velocity.
dlzc
On Dec 20, 9:39 am, Kumar <lordshiva5...@gmail.com> wrote:
> On Dec 20, 9:35 pm, Sam Wormley <sworml...@gmail.com> wrote:
>
>
>
> > On 12/20/09 10:21 AM, Kumar wrote:
>
> > > On Dec 20, 7:20 pm, Sam Wormley<sworml...@gmail.com> wrote:
> > >> On 12/20/09 6:48 AM, Kumar wrote:
>
> > >>> 1. Suppose if we make a straight hole
> > >>> through the earth from one end to other,
...
> > > Thanks. How center of earth is important
> > > in gravity?
>
> > Gravitation decreases on the way to the
> > center, but velocity is increase all the way
> > to the center reaching v_max at the
> > earth's center.
>
> Whether velocity is not related to gravity?
Velocity is related to acceleration.
> Should velocity not decrease due to decrease
> in gravitation?
Consider a pendulum. Does it stop when it reaches the bottom of its
arc? You simply propose a more "simple" pendulum.
David A. Smith
Sam Wormley
Gravitation is a force, F = ma = dp/dt, and as long as it is
not zero will continue to accelerate the falling object.
Uncle Al
[snip muddled crap]
> Velocity is related to acceleration.
[snip rest of crap]
A billiard ball at rest upon the surface of a billiard table
experiences 9.8 g/sec^2 gravitational acceleration downward toward the
center of the Earth. What is its observed velocity three days later?
--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz4.htm
Peter Webb
"Uncle Al" <Uncl...@hate.spam.net> wrote in message
news:4B2ED772...@hate.spam.net...
> dlzc wrote:
> [snip muddled crap]
>
>> Velocity is related to acceleration.
> [snip rest of crap]
>
> A billiard ball at rest upon the surface of a billiard table
> experiences 9.8 g/sec^2 gravitational acceleration downward toward the
> center of the Earth. What is its observed velocity three days later?
>
No, a billiard ball at rest upon the surface of a billiard table does *not*
experience a 9.8 m/s^2 gravitational acceleration towards the centre of the
earth. If it is at rest, it isn't accelerating, by definition of
acceleration (2nd derivative of posn).
Kumar
>
> - Show quoted text -
Whether falling on moon will not be slower due to weaker gravity than
earth?
Kumar
Whether acceleration is not related to gravity?
Kumar
>
> - Show quoted text -
How pendulum will behave, if suppose it is in no gravity influence?
Sam Wormley
> dlzc wrote:
> [snip muddled crap]
>
>> Velocity is related to acceleration.
> [snip rest of crap]
>
> A billiard ball at rest upon the surface of a billiard table
> experiences 9.8 g/sec^2 gravitational acceleration downward toward the
> center of the Earth. What is its observed velocity three days later?
>
>
A billiard ball at rest upon the surface of a billiard table
experiences a net force of zero, confirmed by observation possibly
three days later.
Velocity, i.e., the time derivative of velocity is the definition
of acceleration, so it seems appropriate to say that velocity and
acceleration are related in that a = dv/dt .
dlzc
On Dec 20, 8:40 pm, Kumar <lordshiva5...@gmail.com> wrote:
> On Dec 20, 10:37 pm, dlzc <dl...@cox.net> wrote:
> > On Dec 20, 9:39 am, Kumar <lordshiva5...@gmail.com> wrote:
...
> > > Should velocity not decrease due to decrease
> > > in gravitation?
>
> > Consider a pendulum. Does it stop when it reaches
> > the bottom of its arc? You simply propose a more
> > "simple" pendulum.
>
> How pendulum will behave, if suppose it is in no gravity
> influence?
You did not answer my question. At the bottom of its arc, the
pendulum has no motion in the direction that gravity pulls it. Yet it
keeps moving. Conservation of momentum.
In the absence of gravity, the pendulum will keep doing whatever it
was doing before. Use your head for something other than banging on
the keyboard.
David A. Smith
dlzc
On Dec 20, 7:03 pm, Uncle Al <Uncle...@hate.spam.net> wrote:
> dlzc wrote:
>
> [snip muddled crap]
>
> > Velocity is related to acceleration.
>
> [snip rest of crap]
>
> A billiard ball at rest upon the surface of a billiard table
> experiences 9.8 g/sec^2 gravitational acceleration
> downward toward the center of the Earth.
Actually, no. The ball is being accelerated into a more-or-less
circular "orbit", by a normal force provided (ultimately) by
lithospheric friction. But you knew this and were acting dumb as
usual.
> What is its observed velocity three days later?
Exactly three days? Would this be sidereal or calendar days? If not
calendar days, what is the exact position on the globe? I'd hate for
you to make a muddled request, you little shit.
David A. Smith
Androcles
"dlzc" <dl...@cox.net> wrote in message
news:ecc34a39-9f20-438e...@g4g2000pri.googlegroups.com...
Dear Uncle Al:
On Dec 20, 7:03 pm, Uncle Al <Uncle...@hate.spam.net> wrote:
> dlzc wrote:
>
> [snip muddled crap]
>
> > Velocity is related to acceleration.
>
> [snip rest of crap]
>
> A billiard ball at rest upon the surface of a billiard table
> experiences 9.8 g/sec^2 gravitational acceleration
> downward toward the center of the Earth.
Actually, no. The ball is being accelerated into a more-or-less
circular "orbit", by a normal force provided (ultimately) by
lithospheric friction. But you knew this and were acting dumb as
usual.
========================================
Actually no. A ball at rest is unaccelerated.
Some idiots don't know the difference between force and
acceleration and haven't heard of Newton's third law.
But neither of you know this and are dumb as usual.
<snip rest of muddled crap>
Kumar
> Dear Kumar:
>
> On Dec 20, 8:40 pm, Kumar <lordshiva5...@gmail.com> wrote:
>
> > On Dec 20, 10:37 pm, dlzc <dl...@cox.net> wrote:
> > > On Dec 20, 9:39 am, Kumar <lordshiva5...@gmail.com> wrote:
> ...
> > > > Should velocity not decrease due to decrease
> > > > in gravitation?
>
> > > Consider a pendulum. Does it stop when it reaches
> > > the bottom of its arc? You simply propose a more
> > > "simple" pendulum.
>
> > How pendulum will behave, if suppose it is in no gravity
> > influence?
>
> You did not answer my question. At the bottom of its arc, the
> pendulum has no motion in the direction that gravity pulls it. Yet it
> keeps moving. Conservation of momentum.
gravity. Anyway, which force is applied which make pendulum to move in
opposite direction?
dlzc
On Dec 21, 1:27 am, Kumar <lordshiva5...@gmail.com> wrote:
> On Dec 21, 10:38 am, dlzc <dl...@cox.net> wrote:
> > On Dec 20, 8:40 pm, Kumar <lordshiva5...@gmail.com> wrote:
> > > On Dec 20, 10:37 pm, dlzc <dl...@cox.net> wrote:
> > > > On Dec 20, 9:39 am, Kumar <lordshiva5...@gmail.com> wrote:
> > ...
> > > > > Should velocity not decrease due to decrease
> > > > > in gravitation?
>
> > > > Consider a pendulum. Does it stop when it reaches
> > > > the bottom of its arc? You simply propose a more
> > > > "simple" pendulum.
>
> > > How pendulum will behave, if suppose it is in no
> > > gravity influence?
>
> > You did not answer my question. At the bottom of its
> > arc, the pendulum has no motion in the direction that
> > gravity pulls it. Yet it keeps moving. Conservation of
> > momentum.
>
> The reason can also be that pendulum is bound & can't
> move towards gravity.
No, this cannot be "the reason". The inference is to your proposed
setup. Do you accept that a body falling down your hole has momentum,
and that even though gravitational acceleration is zero at "the center
of the Earth", the faller will continue on?
> Anyway, which force is applied which make pendulum
> to move in opposite direction?
The contact force holding up the pivot for the pendulum.
David A. Smith
Kumar
resisted by some force. If gravitational force is zero, faller can
continue. But this may not be a case with pendulum.
> > Anyway, which force is applied which make pendulum
> > to move in opposite direction?
>
> The contact force holding up the pivot for the pendulum.
Greg Neill
> I think.as per newton's law, things tend to remain in motion unless
> resisted by some force. If gravitational force is zero, faller can
> continue. But this may not be a case with pendulum.
Conservation of momentum:
Not only is it a good idea, it's the law!
dlzc
On Dec 21, 8:58 am, Kumar <lordshiva5...@gmail.com> wrote:
> On Dec 21, 7:44 pm, dlzc <dl...@cox.net> wrote:
...
> > No, this cannot be "the reason". The inference is
> > to your proposed setup. Do you accept that a
> > body falling down your hole has momentum, and
> > that even though gravitational acceleration is zero
> > at "the center of the Earth", the faller will continue
> > on?
>
> I think.as per newton's law, things tend to remain
> in motion unless resisted by some force. If
> gravitational force is zero, faller can continue. But
> this may not be a case with pendulum.
It is at the instant it at the bottom of its swing. It would be for
your faller at the instant he / she crosses Earth's center. Then they
will slow down past center, come to a stop for an instant, and swing
back.
> > > Anyway, which force is applied which make
> > > pendulum to move in opposite direction?
>
> > The contact force holding up the pivot for the
> > pendulum.
> How?
The weight on the pendulum wants to follow an elliptical orbit that
will pass very near the center of the Earth (and is at apoapsis). The
supporting force of Earth's surface can only express as a tension
(well, theoretically) in the member attached to the "bob". Sometimes
the tension force is exactly aligned with the bob's tendency to follow
its orbit, and no change in arc speed is seen. Sometimes it has a
significant component that is oriented along the arc, and a large
change in arc / path speed is seen. The only forces required are
contact forces, when seen in this way.
A lot harder to say than "gravity did it", but Newton was never very
happy with that description either. It wasn't right in his written
opinion, but it worked.
David A. Smith
Kumar
Conservation of momentum looks to be an interesting subject. Will you
tell more about it, which force mediate it?
Kumar
It is bit more technical for me. Is there any way, when we can
experiment ot test a concept without the influence of gravity? Can
earth''s magnetic field also attract things other than magenetic
substances?
As per my expriment mentioned in OP, I think pressure & air can't be a
reason to the attraction towards earth. I think, EM & Gravity forces
can only influence an object in closed & vacumed container. Ok? I
think,light can also be resisted to go into a closed & vacumed
container if it is painted black. Now balance forces will be heat,
magnetic field, non-visible waves & gravity. Ok?
dlzc
On Dec 21, 9:07 pm, Kumar <lordshiva5...@gmail.com> wrote:
...
> It is bit more technical for me. Is there any way,
> when we can experiment ot test a concept without
> the influence of gravity? Can earth''s magnetic field
> also attract things other than magenetic substances?
All substances are either ferromagnetic (strong effect like iron),
paramagnetic (weak effect), or diamagnetic (weak effect and oppositely
affected). But magnetism is "polar", is not as "uniform" as gravity.
> As per my expriment mentioned in OP, I think
> pressure & air can't be a reason to the attraction
> towards earth. I think, EM & Gravity forces can only
> influence an object in closed & vacumed container.
> Ok?
We know that "pressure and air" only provide drag, and do not diminish
gravitation.
> I think,light can also be resisted to go into a closed
> & vacumed container if it is painted black. Now balance
> forces will be heat, magnetic field, non-visible waves &
> gravity. Ok?
When you have your answer to your original question, then you show
that you understand it, why do you then wander off in the woods and
make up dumb problems? Little of what you said is reasonable. So,
"no, not OK".
David A. Smith
Kumar
Sorry, then which forces can be applied in a closed & vacumed glass
bottle?
dlzc
On Dec 22, 4:09 am, Kumar <lordshiva5...@gmail.com> wrote:
> On Dec 22, 9:48 am,dlzc<dl...@cox.net> wrote:
> > On Dec 21, 9:07 pm, Kumar <lordshiva5...@gmail.com> wrote:
...
> Sorry, then which forces can be applied in a closed
> & vacumed glass bottle?
Start another thread. Your misunderstandings and questions about the
hole through the Earth have been answered to your satisfaction.
In answer to this question, "all of them". All you eliminate with the
vacuum is the ability for variations in air pressure to distort
things. Neutrons have been bounced in a vacuum panets orbit in
vacuum, CRT-based displays move electrons around with EM, and there is
no air pressure at the nuclear level where the strong and weak nuclear
forces play.
David A. Smith
PD
> Hello,
>
> I am trying to find awnsers to following questions:-
>
> 1. Suppose if we make a straight hole through the earth from one end
> through the earth or not?
Depends on whether it's coated with Vaseline.
>
> 2. Which type of potential energy is related to which fundamental
> force? Eg. gravitational potential force to gravity.
Electrostatic potential force to Electrostatic force.
There, done. That was easy.
>
> 3. When a ball hit the ground it came back. Is it a repulsion or push
> from earth?
Yes. Push = repulsion.
>
> In a simple experiment, I put a small object in a glass bottle,
> vacumed it by pulling air from mouth & then I reversed bottle
> position. As that object also moved & came to mouth side from bottom,
> is it sufficient to tell, gravity is not a centrpetal force due to its
> revolution or a tornado effect or an atmospheric pressure pushing an
> object down to earth surface?
>
> Best regards.
PD
> On Dec 20, 7:20 pm, Sam Wormley <sworml...@gmail.com> wrote:
>
> > On 12/20/09 6:48 AM, Kumar wrote:
>
> > > through the earth or not?
>
> > along the earth's axis of rotation, one would expect an object
> > dropped in to reach the same height from the center of earth's
> > mass on the other side.
>
> > Start with the differential equation F = dp/dt
>
If there weren't a center to the earth, gravity wouldn't know which
way to point.
PD
Throw a quarter up in the air and watch its velocity decrease on the
way up. Do you think gravity is decreasing on that short trip?
PD
Like a stick.
PD
> On Dec 21, 10:38 am, dlzc <dl...@cox.net> wrote:
>
> > Dear Kumar:
>
> > On Dec 20, 8:40 pm, Kumar <lordshiva5...@gmail.com> wrote:
>
> > > On Dec 20, 10:37 pm, dlzc <dl...@cox.net> wrote:
> > > > On Dec 20, 9:39 am, Kumar <lordshiva5...@gmail.com> wrote:
> > ...
> > > > > Should velocity not decrease due to decrease
> > > > > in gravitation?
>
> > > > Consider a pendulum. Does it stop when it reaches
> > > > the bottom of its arc? You simply propose a more
> > > > "simple" pendulum.
>
> > > How pendulum will behave, if suppose it is in no gravity
> > > influence?
>
> > You did not answer my question. At the bottom of its arc, the
> > pendulum has no motion in the direction that gravity pulls it. Yet it
> > keeps moving. Conservation of momentum.
>
> The reason can also be that pendulum is bound & can't move towards
> gravity. Anyway, which force is applied which make pendulum to move in
> opposite direction?
A pendulum moves back and forth. Are you asking about the force that
makes it move forth and back?
PD
Force of logic sure ain't it, it appears.
PD
Campbell's Cream of Force soup.
dlzc
On Dec 20, 5:48 am, Kumar <lordshiva5...@gmail.com> wrote:
...
> I am trying to find awnsers to following questions:-
>
> 1. Suppose if we make a straight hole through the
> earth from one end to other, seal hole with a pipe &
> put one stick in it, will it pass through the earth or
> not?
Covered. And you now know how.
> 2. Which type of potential energy is related to
> which fundamental force? Eg. gravitational potential
> force to gravity.
Let's add:
- current flow stored in a superconductor, to be tapped for energy
(force: EM)
- electrical energy stored in the form of "chemical energy", released
to drive cars or mentos-diet soda experiments on TV (force: EM)
- thermal energy stored in hot rocks in daytime, used to heat a house
at night (force: inertial)
- rotational energy stored in massive rotors when power is cheaper,
and paid out through generators when power is more expensive. (force:
inertial)
- nucleons shoved into a nucleus other than iron, used in fission /
fusion reactions to generate energy (force: strong and / or weak
interaction forces)
> 3. When a ball hit the ground it came back. Is
> it a repulsion or push from earth?
Lithospheric friction kept it from passing through the Earth. The
rubber of the ball did not have enough loss to consume all the energy
of the ball, so it was "pushed" back from the Earth... usually called
an "impulse" if you want to consult Newton on the subject.
> In a simple experiment, I put a small object in
> a glass bottle, vacumed it by pulling air from
> mouth & then I reversed bottle position. As that
> object also moved & came to mouth side from
> bottom, is it sufficient to tell, gravity is not a
> centrpetal force due to its revolution or a tornado
> effect or an atmospheric pressure pushing an
> object down to earth surface?
Your apparatus does eliminate "tornado effect", and "atmospheric
pressure". But other observations eliminate those as well.
Centripetal force is insufficient to describe gravity, and would have
the wrong sign anyway. What it does describe is why the Mississippi
river (for example) only lowers its surface elevation 50 feet in the
hundreds of miles it travels across land... when compared to sea
level.
David A. Smith
Kumar
Whether close bottle & vacume in it does not resist pressure & air in
it?
Kumar
> On Dec 20, 6:48 am, Kumar <lordshiva5...@gmail.com> wrote:
>
> > Hello,
>
> > I am trying to find awnsers to following questions:-
>
> > 1. Suppose if we make a straight hole through the earth from one end
> > to other, seal hole with a pipe & put one stick in it, will it pass
> > through the earth or not?
>
> Depends on whether it's coated with Vaseline.
>
>
> > 2. Which type of potential energy is related to which fundamental
> > force? Eg. gravitational potential force to gravity.
>
> Electrostatic potential force to Electrostatic force.
> There, done. That was easy.
Are you relating with fundamental forces?
I think weak & strong fundamental forces are related to nuclear
potential energy.
>
>
>
> > 3. When a ball hit the ground it came back. Is it a repulsion or push
> > from earth?
>
> Yes. Push = repulsion.
Is it a push from gravity?
>
>
>
>
> > In a simple experiment, I put a small object in a glass bottle,
> > vacumed it by pulling air from mouth & then I reversed bottle
> > position. As that object also moved & came to mouth side from bottom,
> > is it sufficient to tell, gravity is not a centrpetal force due to its
> > revolution or a tornado effect or an atmospheric pressure pushing an
> > object down to earth surface?
>
> > Best regards.- Hide quoted text -
Kumar
>
> - Show quoted text -
If it is attractive force both way from the center point, how stick
can pass through the earth via piped hole?
Kumar
>
> - Show quoted text -
Yes but other resistances(air pressure, magnetic field, EM? etc. in
air can also effect it.
Kumar
>
> - Show quoted text -
Which force control conservation of momentum?
Kumar
>
> - Show quoted text -
Back force?
Kumar
Whether such forth & back movevents are similarily common in
influence of all forces or without influence of any force?
Kumar
>
> - Show quoted text -
????
Kumar
> Dear Kumar:
>
> On Dec 20, 5:48 am, Kumar <lordshiva5...@gmail.com> wrote:
> ...
>
> > I am trying to find awnsers to following questions:-
>
> > 1. Suppose if we make a straight hole through the
> > earth from one end to other, seal hole with a pipe &
> > put one stick in it, will it pass through the earth or
> > not?
>
> Covered. And you now know how.
>
> > 2. Which type of potential energy is related to
> > which fundamental force? Eg. gravitational potential
> > force to gravity.
>
> Let's add:
Thanks.
> - current flow stored in a superconductor, to be tapped for energy
> (force: EM)
> - electrical energy stored in the form of "chemical energy", released
> to drive cars or mentos-diet soda experiments on TV (force: EM)
> - thermal energy stored in hot rocks in daytime, used to heat a house
> at night (force: inertial)
> - rotational energy stored in massive rotors when power is cheaper,
> and paid out through generators when power is more expensive. (force:
> inertial)
> - nucleons shoved into a nucleus other than iron, used in fission /
> fusion reactions to generate energy (force: strong and / or weak
> interaction forces)
Please clear inertial force meaning. It is gravity?
> > 3. When a ball hit the ground it came back. Is
> > it a repulsion or push from earth?
>
> Lithospheric friction kept it from passing through the Earth. The
> rubber of the ball did not have enough loss to consume all the energy
> of the ball, so it was "pushed" back from the Earth... usually called
> an "impulse" if you want to consult Newton on the subject.
Please tell me more about it.
> > In a simple experiment, I put a small object in
> > a glass bottle, vacumed it by pulling air from
> > mouth & then I reversed bottle position. As that
> > object also moved & came to mouth side from
> > bottom, is it sufficient to tell, gravity is not a
> > centrpetal force due to its revolution or a tornado
> > effect or an atmospheric pressure pushing an
> > object down to earth surface?
>
> Your apparatus does eliminate "tornado effect", and "atmospheric
> pressure". But other observations eliminate those as well.
> Centripetal force is insufficient to describe gravity, and would have
> the wrong sign anyway. What it does describe is why the Mississippi
> river (for example) only lowers its surface elevation 50 feet in the
> hundreds of miles it travels across land... when compared to sea
> level.
>
> David A. Smith
How can we measure gravity without influence of any other force?
PD
Also relevant for back force.
Push a spring. Notice the spring pushes back.
Pull a spring. Notice the spring pulls back.
Same force, same spring.
Hmmmmmm........
PD
All of them.
PD
This doesn't change the fact that gravitation is responsible for
slowing the quarter on the way up.
PD
Same way when a child swings on a swing at the playground, the child
can pass through the bottom of the arc, even though gravity pulls the
child toward the center from either direction.
Does it confuse you that a child on a playground swing does this?
PD
> On Dec 22, 11:33 pm, PD <thedraperfam...@gmail.com> wrote:
>
>
>
> > On Dec 20, 6:48 am, Kumar <lordshiva5...@gmail.com> wrote:
>
> > > Hello,
>
> > > I am trying to find awnsers to following questions:-
>
> > > 1. Suppose if we make a straight hole through the earth from one end
> > > to other, seal hole with a pipe & put one stick in it, will it pass
> > > through the earth or not?
>
> > Depends on whether it's coated with Vaseline.
> If coated Vaseline?
>
> > > 2. Which type of potential energy is related to which fundamental
> > > force? Eg. gravitational potential force to gravity.
>
> > Electrostatic potential force to Electrostatic force.
> > There, done. That was easy.
>
> Are you relating with fundamental forces?
>
> I think weak & strong fundamental forces are related to nuclear
> potential energy.
Yes, that too.
>
> > > 3. When a ball hit the ground it came back. Is it a repulsion or push
> > > from earth?
>
> > Yes. Push = repulsion.
>
> Is it a push from gravity?
No, it is a push from the ground that it bounced off from. If you
remove the ground by digging a hole, you'll notice that the ball
doesn't bounce back up any more. Does this seem complicated to you?
Kumar
>
> - Show quoted text -
"Restoring force, in a physics context, is a variable force that gives
rise to an equilibrium in a physical system. If the system is
perturbed away from the equilibrium, the restoring force will tend to
bring the system back toward equilibrium.
An example is the action of a spring: an idealized spring exerts a
force that is proportional to the amount of deformation of the spring.
Pulling the spring to a longer configuration causes it to exert a
force that brings the spring back toward its equilibrium length. The
amount of force can be determined by multiplying the spring constant
of the spring by the amount of stretch.
Restoring forces do not necessarily cancel out a perturbation
entirely. For example, taut piano strings have a strong restoring
force that gives rise to an equilibrium when the string is straight. A
struck piano string does not return directly to the straight
equilibrium; rather, it oscillates, causing the piano to emit a
particular musical note."
http://en.wikipedia.org/wiki/Restoring_force
I think, above is more relevant. What is restoring force?
Kumar
>
> - Show quoted text -
I think it is indicated in following quote;
"Overview..
The more formal definition is that potential energy is the energy
difference between the energy of object in a given position and its
energy at a reference position.
There are various types of potential energy, each associated with a
particular type of force. More specifically, every conservative force
gives rise to potential energy. For example, the work of elastic force
is called elastic potential energy; work of gravitational force is
called gravitational potential energy, work of the Coulomb force is
called electric potential energy; work of strong nuclear force or weak
nuclear force acting on the baryon charge is called nuclear potential
energy; work of intermolecular forces is called intermolecular
potential energy. Chemical potential energy, such as the energy stored
in fossil fuels, is the work of the Coulomb force during rearrangement
of mutual positions of electrons and nuclei in atoms and molecules.
Thermal energy usually has two components: the kinetic energy of
random motion of particles and potential energy of their mutual
positions.
http://en.wikipedia.org/wiki/Potential_energy "
However it is not directly indicated that which fundamental force is
related to which type of PE. Can you clear it?
Kumar
May be.
Why center point of earth or any substance has gravitational
importance?
In a wave or in a vibration or in a moving pendulum, why center of
these is important & stable? I can't say that it is mediater &
attractive to other momentums?
PD
Any of the four fundamental forces can be a restoring force.
PD
>
> However it is not directly indicated that which fundamental force is
> related to which type of PE. Can you clear it?
Because any force can contribute to the energy.
PD
It doesn't. What makes you think it does?
dlzc
On Dec 22, 10:31 pm, Kumar <lordshiva5...@gmail.com> wrote:
...
> Whether close bottle & vacume in it does not
> resist pressure & air in it?
I see the question mark, but I don't see the question. *You*
established that there was a bottle, and that it was closed. So *you*
made it "resist pressure & air".
David A. Smith
dlzc
Now you get to an interesting question! I mean there is kinetic
energy that is "naturally" confined to a small space. This kinetic
energy can be tapped, just like it was potential energy. But does
gravitation arise from the "field" that also makes inertia... I don't
know.
> > 3. When a ball hit the ground it came back. Is
> > > it a repulsion or push from earth?
>
> > Lithospheric friction kept it from passing through
> > the Earth. The rubber of the ball did not have
> > enough loss to consume all the energy of the
> > ball, so it was "pushed" back from the Earth...
> > usually called an "impulse" if you want to
> > consult Newton on the subject.
>
> Please tell me more about it.
I am not Newton. You should do your own search.
http://en.wikipedia.org/wiki/Impulse
> > > In a simple experiment, I put a small object in
> > > a glass bottle, vacumed it by pulling air from
> > > mouth & then I reversed bottle position. As that
> > > object also moved & came to mouth side from
> > > bottom, is it sufficient to tell, gravity is not a
> > > centrpetal force due to its revolution or a tornado
> > > effect or an atmospheric pressure pushing an
> > > object down to earth surface?
>
> > Your apparatus does eliminate "tornado effect",
> > and "atmospheric pressure". But other
> > observations eliminate those as well.
> > Centripetal force is insufficient to describe gravity,
> > and would have the wrong sign anyway. What it
> > does describe is why the Mississippi river (for
> > example) only lowers its surface elevation 50 feet
> > in the hundreds of miles it travels across land...
> > when compared to >sea level<.
[ incorrect: when compared to distance between surface and center-of-
Earth]
> How can we measure gravity without influence of
> any other force?
Easy. Quantify the other forces, and factor them out. Either by
measurement, or experimental design.
David A. Smith
Javi
At the center of the earth, gravity is zero. But the stick has a velocity.
When you dropped it, velocity was 0 and potential energy was GMm/r. At the
center, all the initial potential energy is transformed into kinetic energy,
so K=(1/2)mv^2=GMm/r, thus v=sqrt(2GM/r). As the forces are null, and it has
velocity, it continues past the center, and the kinetic energy is converted
back into potential energy. Full convertion is achieved at the other side
where potential energy is GMm/r again and kinetic is null.
Javi
There is a point for each body, that, to simplify calculus, can be
considered to have the whole mass of the body, and the gravity field OUTSIDE
the body is equivalent to that of the body.
Kumar
>
> - Show quoted text -
Thanks. Are we trying to know one force (unification) over all ?
Kumar
>
> - Show quoted text -
I think you meant both kinetic & potential energy. Thanks.
Kumar
>
> Show quoted text -- Hide quoted text -
>
> - Show quoted text -
Because in calculation, center point of any substance is consdered. If
we draw a straight line in center of a wave, it can express as I
thought.
Kumar
I can be wrong but you can clear it.
Kumar
>
> - Show quoted text -
No. But if stick move forward slowly in hole then?
Kumar
Anyway, which forces influence the earth from universe or from other
planets? Are these forces are just attractive forces(gravitational) or
others also(Sunlight?)?
>
Kumar
> > > 3. When a ball hit the ground it came back. Is
> > > > it a repulsion or push from earth?
>
> > > Lithospheric friction kept it from passing through
> > > the Earth. The rubber of the ball did not have
> > > enough loss to consume all the energy of the
> > > ball, so it was "pushed" back from the Earth...
> > > usually called an "impulse" if you want to
> > > consult Newton on the subject.
>
> > Please tell me more about it.
>
> I am not Newton. You should do your own search.http://en.wikipedia.org/wiki/Impulse
>
>
>
>
> > > > In a simple experiment, I put a small object in
> > > > a glass bottle, vacumed it by pulling air from
> > > > mouth & then I reversed bottle position. As that
> > > > object also moved & came to mouth side from
> > > > bottom, is it sufficient to tell, gravity is not a
> > > > centrpetal force due to its revolution or a tornado
> > > > effect or an atmospheric pressure pushing an
> > > > object down to earth surface?
>
> > > Your apparatus does eliminate "tornado effect",
> > > and "atmospheric pressure". But other
> > > observations eliminate those as well.
> > > Centripetal force is insufficient to describe gravity,
> > > and would have the wrong sign anyway. What it
> > > does describe is why the Mississippi river (for
> > > example) only lowers its surface elevation 50 feet
> > > in the hundreds of miles it travels across land...
> > > when compared to >sea level<.
>
> [ incorrect: when compared to distance between surface and center-of-
> Earth]
>
> > How can we measure gravity without influence of
> > any other force?
>
> Easy. Quantify the other forces, and factor them out. Either by
> measurement, or experimental design.
> David A. Smith- Hide quoted text -
>
> - Show quoted text -- Hide quoted text -
Edward Green
<webbfam...@DIESPAMDIEoptusnet.com.au> wrote:
> "Uncle Al" <Uncle...@hate.spam.net> wrote in message
>
> news:4B2ED772...@hate.spam.net...
>
> > dlzc wrote:
> > [snip muddled crap]
>
> >> Velocity is related to acceleration.
>
> > A billiard ball at rest upon the surface of a billiard table
> > experiences 9.8 g/sec^2 gravitational acceleration downward toward the
> > center of the Earth. What is its observed velocity three days later?
>
> No, a billiard ball at rest upon the surface of a billiard table does *not*
> experience a 9.8 m/s^2 gravitational acceleration towards the centre of the
> earth. If it is at rest, it isn't accelerating, by definition of
> acceleration (2nd derivative of posn).
Oh, he's just playing with reference frames.
PD
If that's possible.
PD
Not so. That only applies in spherically symmetric objects. Which
planets happen to be. But in other cases, not.
Javi
No, it applies to any object, no matter the symmetry. There is always a
center of mass. In some cases it may be even out of the object, but the
center of mass exists always.
dlzc
On Dec 25, 5:30 am, Kumar <lordshiva5...@gmail.com> wrote:
> On Dec 24, 4:39 am,dlzc<dl...@cox.net> wrote:
> > On Dec 22, 10:53 pm, Kumar <lordshiva5...@gmail.com> wrote:
...
> > > Please clear inertial force meaning. It is gravity?
>
> > Now you get to an interesting question! I mean
> > there is kinetic energy that is "naturally" confined
> > to a small space. This kinetic energy can be
> > tapped, just like it was potential energy. But does
> > gravitation arise from the "field" that also makes
> > inertia... I don't know.
>
> Pls tell me some more about it.
I cannot tell you more about "I don't know".
...
> > > How can we measure gravity without influence of
> > > any other force?
>
> > Easy. Quantify the other forces, and factor them
> > out. Either by measurement, or experimental
> > design.
>
> Can we make an environment free from gravity in lab?
> If yes how?
There is no gravity in the quantum realm. So that leaves EM. We move
the lab into space and make our tests there.
David A. Smith