Question for mandrin
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Force, as defined at a basic level, is a push or a pull on an object. This can be from something like a hand pushing a door closed or gravity pulling a ball you let go of down to the ground. Centrifugal force as I learned it is not, by definition, a force. It is inertia acting upon an object in motion.
Take a string tied to a ball and swing it around. The ball, if the string was cut, will fly away from you. But is this because the string is pushing on it? No. The string is only pulling on the ball, keeping it from flying away. This is called centripetal force. The ball flys away because of inertia.
I say all of this with a huge grain of salt, however. My physics knowledge comes from the one class I took (in high school
) and I am only trying to help with what I know (or believe to know).
I have a feeling, however, that "inertial force" might be the key to defining what "centrifugal force" is. Me being the physics expert that I am, I have never heard of inertial force.
Mandrin is the expert. He can clear up all the questions surrounding this subject. I hope that my info helped, but I look forward to his response.
Take a string tied to a ball and swing it around. The ball, if the string was cut, will fly away from you. But is this because the string is pushing on it? No. The string is only pulling on the ball, keeping it from flying away. This is called centripetal force. The ball flys away because of inertia.
I say all of this with a huge grain of salt, however. My physics knowledge comes from the one class I took (in high school
) and I am only trying to help with what I know (or believe to know).I have a feeling, however, that "inertial force" might be the key to defining what "centrifugal force" is. Me being the physics expert that I am
, I have never heard of inertial force.Mandrin is the expert. He can clear up all the questions surrounding this subject. I hope that my info helped, but I look forward to his response.
Force, as defined at a basic level, is a push or a pull on an object. This can be from something like a hand pushing a door closed or gravity pulling a ball you let go of down to the ground. Centrifugal force as I learned it is not, by definition, a force. It is inertia acting upon an object in motion.
Take a string tied to a ball and swing it around. The ball, if the string was cut, will fly away from you. But is this because the string is pushing on it? No. The string is only pulling on the ball, keeping it from flying away. This is called centripetal force. The ball flys away because of inertia.
I say all of this with a huge grain of salt, however. My physics knowledge comes from the one class I took (in high school
I have a feeling, however, that "inertial force" might be the key to defining what "centrifugal force" is. Me being the physics expert that I am
Mandrin is the expert. He can clear up all the questions surrounding this subject. I hope that my info helped, but I look forward to his response.
Thanks for the reply. It seems like there's conflicting info out there about what CF is or isn't. Not to mention it's "golf definition".
mandrin
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Bigwill,
Centrifugal and centripetal forces always act together as an action-reaction force pair and come into existence whenever there is some instantaneous or continuous rotation around a center. The centripetal force is the external action force and the centrifugal force is the inertial reaction force.
The centripetal force is the external force employed to constrain the moving mass into the curvilinear motion. It is usually a pulling force from a center or a pushing force from the outside towards a center of rotation.
In the simplest case of a mass whirling in a circle around a center, the cord pulls on the mass with the centripetal force and the centrifugal force, equal but opposite in magnitude, acts on the center.
When scientists use non-inertial reference frames, such as accelerating frames or rotating frames, they have to introduce fictitious inertial forces for Newton Laws to remain valid. Basically it is here the root for the confusion about centrifugal forces and inertial forces to be non-existing, fictitious etc. Too many people dabbling with notions they don’t apprehend.
However, the first to be blamed for the perpetual confusion regarding centrifugal force are the scientists themselves not being precise and consistent with their definitions and use of words in their text books.
Next to blame are a horde of self-acclaimed pseudo scientists, such as Kuykendall and many others, who exploited this absence of clarity by starting to claim, sometimes very aggressively, that it is all a hoax, fictitious, does not exist, etc., etc..
The usual mistakes/arguments are:
-1- Simply denying its existence.
Claiming the non-existence of centrifugal force, one also destroys the bedrock of Newtonian physics since it implies denying the validity of Newton’s Third Law. Forces ALWAYS come in pairs. For every centripetal force there is always a centrifugal force.
-2- Argumenting that assuming that it existed and it being equal and opposing in value to centripetal force it could not exist since it would cancel the centripetal force.
This shows also a fundamental misunderstanding of Newton’s third law. These two forces don’t act on the same object and hence can’t cancel each other.
-3- Assuming that the golf swing should be treated in a non-inertial rotating reference frame and hence considering centrifugal force as fictitious.
Completely confusing things. A golfer is simply operating in an (quasi) inertial reference frame and definitely subjected to Newton’s Law’s without having to introduce fictitious forces when operating in non-inertial rotating frames.
-4- Considering, like holeout,
that centrifugal force isn’t really a force but rather inertia, acting upon an object in motion. Inertia is NOT a force, it is an intrinsic property of matter. It is the name given to the characteristic that all matter resists having its motion changed. It is simply a descritption of a property for which we have no real explanation.
For those, quite many, who deny the existence of inertial forces, such as centrifugal force, why not have someone drop a brick on your head from quite some height, and if you survive and still convinced, please, tell the world that inertial forces don’t exist.
It is realy pathetic that inertial forces are being considered as non existing by many. It is actually the most common force around. Whenever there is motion of matter of any kind there are inertial forces. Darned REAL forces, nothing fictious about them; they can do lots of damage.
Ask Brain Manzella if he considers the huge inertial forces generated by big waves smashing dikes to pieces as being a hoax, fictitious, non really existing. But keep at a save distance. He might just use that ‘non-existing’ ‘fictitious’ inertial centrifugal force generated with a golf club to show you his vigorous point of view.
Bigwill,
Centrifugal and centripetal forces always act together as an action-reaction force pair and come into existence whenever there is some instantaneous or continuous rotation around a center. The centripetal force is the external action force and the centrifugal force is the inertial reaction force.
The centripetal force is the external force employed to constrain the moving mass into the curvilinear motion. It is usually a pulling force from a center or a pushing force from the outside towards a center of rotation.
In the simplest case of a mass whirling in a circle around a center, the cord pulls on the mass with the centripetal force and the centrifugal force, equal but opposite in magnitude, acts on the center.
When scientists use non-inertial reference frames, such as accelerating frames or rotating frames, they have to introduce fictitious inertial forces for Newton Laws to remain valid. Basically it is here the root for the confusion about centrifugal forces and inertial forces to be non-existing, fictitious etc. Too many people dabbling with notions they don’t apprehend.
However, the first to be blamed for the perpetual confusion regarding centrifugal force are the scientists themselves not being precise and consistent with their definitions and use of words in their text books.
Next to blame are a horde of self-acclaimed pseudo scientists, such as Kuykendall and many others, who exploited this absence of clarity by starting to claim, sometimes very aggressively, that it is all a hoax, fictitious, does not exist, etc., etc..
The usual mistakes/arguments are:
-1- Simply denying its existence.
Claiming the non-existence of centrifugal force, one also destroys the bedrock of Newtonian physics since it implies denying the validity of Newton’s Third Law. Forces ALWAYS come in pairs. For every centripetal force there is always a centrifugal force.
-2- Argumenting that assuming that it existed and it being equal and opposing in value to centripetal force it could not exist since it would cancel the centripetal force.
This shows also a fundamental misunderstanding of Newton’s third law. These two forces don’t act on the same object and hence can’t cancel each other.
-3- Assuming that the golf swing should be treated in a non-inertial rotating reference frame and hence considering centrifugal force as fictitious.
Completely confusing things. A golfer is simply operating in an (quasi) inertial reference frame and definitely subjected to Newton’s Law’s without having to introduce fictitious forces when operating in non-inertial rotating frames.
-4- Considering, like holeout,
Inertia is NOT a force, it is an intrinsic property of matter. It is the name given to the characteristic that all matter resists having its motion changed. It is simply a descritption of a property for which we have no real explanation.
For those, quite many, who deny the existence of inertial forces, such as centrifugal force, why not have someone drop a brick on your head from quite some height, and if you survive and still convinced, please, tell the world that inertial forces don’t exist.
It is realy pathetic that inertial forces are being considered as non existing by many. It is actually the most common force around. Whenever there is motion of matter of any kind there are inertial forces. Darned REAL forces, nothing fictious about them; they can do lots of damage.
Ask Brain Manzella if he considers the huge inertial forces generated by big waves smashing dikes to pieces as being a hoax, fictitious, non really existing. But keep at a save distance. He might just use that ‘non-existing’ ‘fictitious’ inertial centrifugal force generated with a golf club to show you his vigorous point of view.
What is the force that extends the club from its 90* relationship to the left arm, to a straight line relationship, during the downswing, assuming that swing is made without introducing wrist torque to increase the angle? In golf circles, it's centrifugal force; is it really? Why or why not? Thanks
This is so funny. You just can't admit that you're wrong, can you Mandrin. There is no such thing as centrifugal force because if it did exist the instant you let go of a rotating object it would fly STRAIGHT away from the center and not at a 90 degree angle to the radius. There is only momentum/inertia and centripetal force. Rotating frame of reference was never fully explained by Newton since it failed at the point when he tried to describe Space itself as the frame of reference. (see spinning bucket) Thank goodness for people like Leibniz who offered a counter argument to Newton and of course Ernst Mach that founded much of Einsteins theories to dispel this fictitious force and give us general relativity.
Or are you going to do a song and dance about the coriolis effect.
BTW, I didn't have to consult any of my co-workers to bust you on this one.
Or are you going to do a song and dance about the coriolis effect.
BTW, I didn't have to consult any of my co-workers to bust you on this one.
But if you let go of a rotating object (i.e. spinning a ball on a rope in a circle), then wouldn't you eliminate that centripetal force, thereby eliminating the centrifugal force? If forces do indeed come in pairs, then wouldn't this be the case?
Brian Manzella
Administrator
?
I don't get it, Steve.
What is the point? Mandrin is a really smart guy and knows his stuff. This goofy CF or no CF debate is silly.
Just tell us what the reason you are so intent on busting Mandrin's chops?
I don't get it, Steve.
What is the point? Mandrin is a really smart guy and knows his stuff. This goofy CF or no CF debate is silly.
Just tell us what the reason you are so intent on busting Mandrin's chops?
Great post mandrin, best I've ever seen on this subject.
So, if I'm holding a weight dangling on a string, according to Newton the weight is pulling against the string and the string is pulling against the weight.
If I swing the weight in a circle this relationship is the same, except now I have introduced momentum, which means that if I were to let go of the string the momentum of the weight would cause it to fly off in a straight line, tangent to the arc.
When the weight is simply hanging from the string (not in motion) it is creating a force, but when it is moving on an arc we use the term centrifugal force in order to show that the weight is moving on an arc.
Is that about it?
So, if I'm holding a weight dangling on a string, according to Newton the weight is pulling against the string and the string is pulling against the weight.
If I swing the weight in a circle this relationship is the same, except now I have introduced momentum, which means that if I were to let go of the string the momentum of the weight would cause it to fly off in a straight line, tangent to the arc.
When the weight is simply hanging from the string (not in motion) it is creating a force, but when it is moving on an arc we use the term centrifugal force in order to show that the weight is moving on an arc.
Is that about it?
That's the general argument any "Newtonian" physicist will put up. But let me give you the idea which makes this all fall apart.
Imagine you're an ice skater and you're spinning. You will feel the pull on your arms to let them spread apart. But what if we change it so that the ice rink is spinning and you aren't? Shouldn't you still feel the pull on your arms? The frame of reference is rotating, isn't it? According to Newton only one perspective can be right no matter which view point you are looking from. But that means a set of physics for one perspective and a different set of physics for another. And that's why "absolute space" failed.
Mach introduced the idea that if you had only empty space, you would not feel acceleration. According to Mach's theories the force you feel is proportional to the amount of matter in the universe. From this concept you got a lot of Einsteins theories on relative motion because all motion (including spinning) is relative to other objects in space.
Because he took a thread of mine and made it a personal attack... and he thinks he's always right. Anyone else is just a looser to him and that pisses me off. So someone else needs to show him what it's like to be an arrogant pr*** toward him when he's wrong.
I'm confused. If you wanted to have the same "relative motion" then the rink wouldn't spin at all. It would move in a manner in which the object (let's go back to spinning a ball on a string again) would move relatively the same. If the ball spins around its center, a given part of the ring would relatively move closer to, then away from the ball (and to the side some as well). It's hard for me to describe in writing, but it makes sense in my head
. But the rink would definitely not spin.And I'm still confused about what relative motion has to do with forces.
shortgamer
New
From all the discussion between the two of you I get the feeling that you take it personal and he's just having fun.
Brian Manzella
Administrator
A little advice from a (getting smarter everyday) 45 yr old.
Steve (Ringer),
I'll bet $1000 cash that Mandrin knows more science than you.
Play dumb and soak it up, then go do with it what you wish.
It works.
Steve (Ringer),
I'll bet $1000 cash that Mandrin knows more science than you.
Play dumb and soak it up, then go do with it what you wish.
It works.
Just reposting the question so it dosen't get lost...
Since we seem to be doing a physics debate....
In the ice rink spinning example, I assume the skater wouldn't feel pull for exactly the reason pointed out in the second paragraph. The skater is not moving relative to all objects in space, but just the ice rink which is just a blip in the universe.
mandrin
New
Ringer,
I can see that you have been skimming quickly through some sites to pick up a few notions and to drop a few big names just so to impress people. I will be really generous and not ask you to explain it all to us.
Perhaps you should have asked your co-workers for advice since it is you completely busting the little credibility you have left regarding scientific matters. Indeed you are just yet another time making a complete fool of yourself with your ‘scientific’ arguments, the basic fallacy neatly pointed out by holeout in his post #28 below yours.
(holeout) “But if you let go of a rotating object (i.e. spinning a ball on a rope in a circle), then wouldn't you eliminate that centripetal force, thereby eliminating the centrifugal force? If forces do indeed come in pairs, then wouldn't this be the case?”
I am fairly certain that you picked your argument from that truly hilarious character Jack Kuykendall, who claims to be the greatest golf scientist on earth. I can assure you that he is not!
I knew from the very start that you were desperately looking for something, some little crack to wiggle inside. You really are like a pit-bull, just not readily giving up. Better luck next time. Lots of fun. Keep trucking.
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