Rotational Physics in Tricking

[Skilzat85X]

I'm planning on wrapping up a (redundant) article dealing with certain physical principles and their application to tricking in the coming months, so I thought I'd throw this topic out there for the big boys to just toss around ideas and concepts and discuss or debate a little if necessary.

Mostly, to see if separate individuals have come to the same conclusions independently, so we're all on the same page, and just have all kinds of fun.

So, what are some thoughts or interesting things you've noticed or looked into in relation to physics and tricking? In this topic we'll specifically focus on matters doing with rotation physics; angular velocity, angular momentum, rotational (moment of) inertia, torque etc.

I can't say this topic is inherently going to help people out with tricks, this is a little more "under the hood" type discussion. That is to say, it's more seeing why or how things work instead of proposing action to take. Knowledge for knowledge's sake, yeno?

Have fun!

[tigtricker]

sometimes i think about this, and i have some ideas, but i can't be bothered to rigorously lay anything out. maybe i will do now you have made this thread skilz! i will watch it carefully. In general it is not particularly useful to try and analyse tricks in this way since most technique has been figured out with intuition and experiment (of course you know this), though perhaps this thread could go some way to eliminate some of the fundemental misconceptions about mechanics that occasionally surface in the community.

[Source]

My issues with rotational physics in tricking are the huge misunderstandings that I hear passed off as fact by 'experienced' trickers. Actually that extends to much more than just rotation...

[Skilzat85X]

My issues with rotational physics in tricking are the huge misunderstandings that I hear passed off as fact by 'experienced' trickers. Actually that extends to much more than just rotation...
Yea definitely haha. Care to share any of these? :smile:


Yeno if you wanna talk about more than rotation of course it's fine haha I'm not picky about the discussion as long as it's within the realms of awesomeness.

[Source]

The one about blocking always really gets to me.
When I hear someone tell another person that you need to block to land an aerial I shudder. That is just one example. But it gets thrown around that to land any trick you need to block.
Blocking is for rebounding.

[simon]

haha i knew tom would speed into this thread. geeeeeeeeek.

[synd7]

one massive misconception that shits me is that you stop going up once you start twisting. It makes zero fucking sense

[Origional]

What is your target audience?

[DYoo]

ac=[m(v^2)]/2

[Ryan Murray]

Eliminate resistance on the axis of rotation. That's the only physics I have to remind myself about when I trick.

[Ambitrixterous]

In general it is not particularly useful to try and analyse tricks in this way since most technique has been figured out with intuition and experiment

Not this

My issues with rotational physics in tricking are the huge misunderstandings that I hear passed off as fact by 'experienced' trickers. Actually that extends to much more than just rotation...

THIS

one massive misconception that shits me is that you stop going up once you start twisting.

This

Eliminate resistance on the axis of rotation.

This

[simon]

hahahaha.OK DAN

[tigtricker]

Not this


haha i tried to word that in such a way that a confusion like this would be avoided. when i said analyse i meant in a rigorous sense... sitting down and constructing Newton's laws in the context of tricking for the sake of it. Of course thinking of physics in tricking in the way ryan m suggested is perfectly useful, which is what i was implying when i said that things have been figured out through intuition. Hopefully this clears my post up.

*not an aggresive post* but i thought that you made a comment on the video of the guy doing full one way and then back the other is an example of what Source was saying. I am trying to think of some cheap book or something that explains classical mechanics from first principles really well since i would do a terrible job of it.

[Flowers]

I like this thread.



I remember reading a gymnastic science experiment once about some young girl doing a move that they thought was physically impossible for her to do.

I wonder if that was factual or just hysteria

[Adam Ross]

tom can recite pie to the end.

[Ryan Murray]

tom can recite pie to the end.

Most people can do that. It takes a real g to recite pi to the end.

[simon]

lolol adam got owned.

[tigtricker]

Most people can do that. It takes a real g to recite pi to the end.

ahahha

you bring it on yourself adam

[SpyrL]

Most people can do that. It takes a real g to recite pi to the end.

But.. huh?
Pi never ends..

[tigtricker]

But.. huh?
Pi never ends..

....

[Skilzat85X]

Looks like we're building up a queue of fail ahaha.

[JiayoJames]

I find the different positions we need to make while spinning to remain on axis for different types of kicks quite interesting.

[tigtricker]

Looks like we're building up a queue of fail ahaha.

perhaps if you get the ball rolling with the article you mentioned or some thought of yours.

[Skilzat85X]

What is your guys opinion (if any) of the way one's body can be treated both as one object and a group of objects depending on the time, situation, and desired effect?

[AdamSwaluk]

I can only speculate as to what you mean by that, Skilz, having never taken a physics class myself.

Here's a guess; a speculation, if you will: A group of objects works together to accomplish a task (540 kick, for example), each individual object performing a distinct job.

That would be my best guess. Now, if someone would be kind enough to correct me we can progress.

[SpyrL]

What is your guys opinion (if any) of the way one's body can be treated both as one object and a group of objects depending on the time, situation, and desired effect?

In my personal opinion, one's body cannot be treated as one object.

I mean obviously its a body, duh thats one thing, but for it to perform its functions it relys on objects "under the hood" to do them. And if one of those objects does not help in completing a specific function, it will not work properly and possibly not at all. Hence it can be seperated into multiple objects.

However, what if one's body is in an immobile state. Then there technically isnt any functions to be performed, and therefore one's body cannot be classed as a group of objects performing a function, but rather just a body.


I hope I havent confused anyone.

and please excuse my referencing to a car whenever I said "under the hood".

[AdamSwaluk]

SpyrL i nedz explinad,, wat is objec & wut iz grup ov objecct?

[Cory]

What is your guys opinion (if any) of the way one's body can be treated both as one object and a group of objects depending on the time, situation, and desired effect?

The following are steps in the process of doing a Round-off_Flashkick

key:

[B][body working as one object]

-reach for the ground with your first arm
-pull your back leg behind you
-reach for the ground with your second arm
-pull your legs together
-whip your legs down to the ground
-bring arms and chest up
-set up
-chamber kick
-extend kick
-pull kick to ground


yeah...that's pretty much it, I guess

[SpyrL]

SpyrL i nedz explinad,, wat is objec & wut iz grup ov objecct?

I have no idea what objec is.
As for grup, I think it is a Romanian word.

[AdamSwaluk]

Would someone be kind enough to explain the definition of both an object and a group of objects?

[Taimatsu]

TRICK2SCIENCE!!!!!!


no moar trick2kill

[Kyle McLean]

just do tricks.

[Skilzat85X]

This whole "forget the science behind tricks" attitude is ludicrous. It's like telling physicists, biologists, any freaking scientists to stop doing what they're doing because it doesn't matter. And yeno what? Half the time science finds something that can be practically beneficial, and the other half the time it's just knowledge for curiosities sake, in other words practically useless haha.

But many people think about these things and want their curiosity satisfied. This isn't a discussion to revolutionize tricking, it's for those individuals who seek to know more about certain principles behind tricks. Useless for anything but knowings sake? Yes. But it's no more practically useless than tricking in itself haha.

Some people just don't care about this stuff. But some do, and nobody should be ostracized for being on either side of this spectrum.

EDIT:
This goes along with the point tigtricker was making that I quite agree with.

It's interesting to study this kinda stuff and see how it all works. But let's face it all this knowledge is still very limited in it's practically, much of it in fact is only useful just for the sake of knowing! You don't see Ott or Anis cracking open a physics book when they want to learn a new trick haha. Much of tricking is learned purely through intuition. Can extra knowledge help speed up this process though? Usually, at least with early beginners with misconceptions. But yea, there's no fooling ourselves into thinking that talking about the physics of tricking is still pretty redundant. But who cares! So is doing tricking in itself haha. It may not get much done, but it's fun. And that's what it's all about!

[Skippy]

Skilzience is the reason Skilz can brandy > flash higher than most can roff flash.

TRICK2SCIENCE!!!!!!


no moar trick2kill

trick2learn.

:]

[Kyle McLean]

skilz im not a scientist.
i dont know shit about physics.
im a 17 year old kid.
who likes to trick.
and honestly i dont care about why tricks work, i have better things to do with my time, like i dunno actually do tricks instead of do math and shit to see why the work.
go do some tricks everyone, they are fun.
honestly i dont want to beable to understand why tricks work or whatever we are even talking about. because i believe that i can do any trick or varaition that i think up and dont need science telling me if i can or can not do it. with enough practice i can do it, no matter what science says.

[Skilzat85X]

skilz im not a scientist.
i dont know shit about physics.
im a 17 year old kid.
who likes to trick.
and honestly i dont care about why tricks work, i have better things to do with my time, like i dunno actually do tricks instead of do math and shit to see why the work.
go do some tricks everyone, they are fun.
honestly i dont want to beable to understand why tricks work or whatever we are even talking about. because i believe that i can do any trick or varaition that i think up and dont need science telling me if i can or can not do it. with enough practice i can do it, no matter what science says.

So are you disagreeing with me...or are you basically just restating everything I just said from your perspective? Haha.

Oh gawd how do I put this...yes I know dude ahahah. That's what I just got done saying. There's nothing wrong with not caring about the science behind tricks. Heck, you're proof you can be freaking awesome about tricks and not give a crap about the technical stuff.

The point I was making is: if you don't care about this stuff, you're not being forced to post in this thread haha. And you shouldn't be forced to be interested in it. If you do care about this stuff, you can post here, and you shouldn't be ostracized for having an interest in it.

[Kyle McLean]

well quite frankly i only read the first sentence of your previous post so im sry for that.

and i understand that some are interested in this, but i personally think if some people spent more time acutally doing tricks instead of studying them they would be so much better. for example most of your pros(with the exception of dan perez) cant tell you how to do tricks, they just do them, trail and error, once you get a move that move helps with the next, like if you can cork and 540 you just add them together and you get a cork swipe looking thing, tricks are really that simple. for example watching anis teach at LK he honestly just doesnt know what he's talking about he would tell campers that for "x" trick do this, when he himself doesnt do it(i do the exact same thing, i pretty much suck at teaching).

im just rambling now, and honestly if someone sat me down and taught me a thing or to about why this trick works when i block at such angle and not at another or whatever it is then i would listen, im just way to lazy to learn it, and like trail and error alot.

[jiayo-chris]

I would see actually tricking and learning about the physics behind it as two totally seperate things. So the argument "if you spent more time tricking and not learning about it ect ect" Is completely invalid because if i read up about tricking it will be during times i can't be tricking physically, therefore it couldn't do anything but benefit me.

[Source]

I also feel that learning the physics or other basic principles behind a trick/movement makes it easier to teach Correctly.
I am a modest tricker. Can't do much but I dont really care. My talent is in breaking skills down and teaching them. Hence I began coaching gymnastics.
And before someone says you don't need physics to teach:
Having a grasp of the concepts behind a move helps Me to teach.

[AdamSwaluk]

I'm afraid I only read the first couple lines of your last post, Kyle, but here's a response nonetheless: If you don't give a shit, don't take part in the discussion.

Edit: Anyone gonna answer my question or what?

[Duke_Hoff]

WHY ISNT EVERYONE AS AWESOME AS GO OUT JUMP AND LEARN IT IMMIDIATELY WAAH!

nice topic skilz :good:

[Ferret]

lol back to the subject of the thread...

[A_Wilhelm]

For the question with one object vs group of objects etc I think, that it only depends on the point of view.

If you are far enough away from something, everything merges into one object (planets, sun systems etc) but as you come nearer everything devides into more and more little objects which are all somehow linked and grouped together (if your focus is wide enough) and slowly loose contact and correlation to each other as your focus gets tighter, until everything that's left is just the smallest particle you focus on with no correlation or contact to anything.

As for tricking (and your question) I think it would be helpfull to treat the human body as one object in all situations where you describe the motion of a trick as a whole (height, direction of rotation, axis, redirection of forces and velocity etc etc), and/or examine it's interaction with outer forces like gravity, air resistance, angles of forces that act on the body or are exerted on the environment by the body.

For all examinations of the inner correlations between the different bodyparts, limbs, muscles etc it would be usefull to treat the body as a group of objects which act together or counteract to aid a certain desired result/motion. This would be far more complex (depending on how much you wnat to go into detail), as you have to to treat every working muscle or musclegroup as a separated object whith different directions, angles and figures of force, which are acting together and/or against each other at different times and for different durations.

I don't know if this is even remotely aiming in the direction you want this discussion to go, and my ideas could be totally off, considering that I'm thinking about all this for the first time because I am not at all interested in physics an math normally. (although it's a different deal when it concerns tricks)

I also can't really imagine how in depth your article about the physics of tricking will be. It could be anything between totally basic physics that doesn't even need to be talked about, and can be understand by every 7th grader, and a fucking hard and complex subject on which I don't really trust a normal pupil (in terms of someone who hasn't studied this exact field of physics at university and has a doctorate at it) to be able to figure out and/or explain it, no matter how good he is at school.
Plainly because physics and math at school are not designed to teach us math and physics, but to teach us logic (which is ofcourse far more important in general)

Ofcourse this opinion could be totally wrong and maybe I'm not giving you the credit you deserve and your whole article will be totally in depth, complex and revolutionaire on the one hand, and really well explained and understandable for everyone on the other hand, and I definately couldn't judge wether it is ingenious or total bullshit.

This was just in concerning the scientific side of your article, I'm 100% sure that the mechanics and basic physical principles will be very well explained.

[With too much in depth I mean things like actually trying to describe tricks with formulas, including forces and angles of forces of every seperated object of the object group, constantly changing angles of forces, linear forces merging into circular motions (wrapping etc), a changing position in the room, which results in different angles in which gravity acts on the body, how air resistance acts on the different objects in the objectgroup/the human body as one object. And all this in one formula which contains everything and still fully describes the trick for the human body as one object, an objectgroup, and serparately for every object in this objectgroup, and all that in correlation to the point in time, timing, and duration, everything occurs. You see I'm just throughing stuff out here, because I can't think of any way such a formula or bunch of formulas could be created to describe a trick, and don't think anyone who isn't a scientist can develop, describe or understand such a formula]

Maybe I'm just dumb and am totally overcomplicating the subject in my head, but yeah, lets see what you and others might come up with.

For now I'm expecting general mechanics of tricks and basic physical principals which can be used to explain why and how tricks work. I think that would be a level on which everyone can take some benefits for his own tricking out of it, and where it's still understandable and applyable to your own technique. A too in depth analysis of tricks would need someone who really knows his stuff about physics, but even then I doubt that it would be understandable.

Edit:

I actually think a discussion about biomechanicle principles and their effect on and proper usage for tricking techniques may be more sufficient then an in depth physical examination of it, but you may mean that anyway.

If that's your intention, basic principles like the maximum starting power, the optimal acceleration distance, the optimal tendency of the acceleration process, the optimal koordination of partial-impulses (the timing of it), counteraction, conservation of momentum and the leading function of the head might be a few easy points that should be mentioned.

(Sorry if that aren't the right terms, I just poorly translated them from german)

[Skilzat85X]

A few individuals have commented so far on the "single object vs multiple" object subject, and so far the only one who took it the way that I was was you A_Whilhem. Of course, everyone else was still right in respect to the directions they took it as well.

Here's my thoughts on that particular subject (mostly just in regards to rotation): since objects maintain a constant rotational velocity unless acted upon by an external force, how does the body changes it's velocity in mid-air? Well, there's that whole reducing the rotational (moment of) inertia thing, but what I'm talking about is how one can generate a force in the air to increase rotational speed as well. And it seems they can do this because the body is a collection of parts, moreover, thanks to our muscles these parts are able to move in mid-air.
So let's say, someone wraps their arms in and all that. Their arms pull as far as they can until they're eventually pulling along with the shoulders, and the shoulders are connected to the core of the body, which means they're exerted a torque on the body, and therefore can increase the rotational speed. Therefore, it's safe to say in such situations the body can act as a collection of independent parts.
However, sometimes the body is treated as one part. Such as when one tucks in really tight, making their entire body rigid, like a ball or rock or something. In this case when all the body parts are connected (sort of, can't think of a better way of explaining) and rigid, the body basically acts as one unit.

Now here's something I've been pondering about: the body (namely, the core of the body) doesn't increase rotational speed until the shoulders exert a torque on it, which is usually caused by the performer pulling their arms in firmly until the shoulders are pulled along with it, or heck just pulling their arms and shoulders.
So hypothetically, someone could keep their arms straight out to the side pointing horizontally and still exert a torque on their body, right?
However, they (their body and core in general) won't spin as fast. So here's what I'm wondering in regards to that:

Do they not spin as fast because with the arms up and out, the arms tend to lag behind causing greater air resistance, which also causes them to sliightly toruqe the body in the opposite rotational direction when they get "caught" at the limits of their ROM. (A case where the body is treated as a group of objects).
OR
Do they not spin as fast simply because their moments of inertia (let's simplify and say radius of their entire body) is larger since their arms are being held out, since a higher rotational inertia means more force is needed to make the object spin faster (and since we're going to be exerting the same toruqe for all intents and purposes), meaning their going to spin slower? (In this case, the body is being treated as one object)

Or perhaps these situations aren't mutually exclusive. Or maybe, as I'm thinking, if the shoulder muscles are locked making the connection between the body and the arms/shoulder rigid, they must have to act as in case two (as one object), and if the shoulders didn't hold themselves and the arms in place rigidly, it must have to act as in case one (as multiple objects exerting forces on each other).

So, maybe I just answered my own question haha, somewhat. That is to say, that perhaps the body parts get treated as one object when the muscles hold them rigidly, and multiple objects when they're not. Well duh, that's pretty obvious. What a waste of typing! Haha.
Wait no I'm still not what to think of the whole spinning with the arms out situation. Wait hmmm ok I think I do now who knows I'm confusing myself haha.

I just wanted to see what you guys thought about that as welll.
(I think that the deepness of tricking knowledge is inversely proportionate to how dang useful it even is hahah).

--------------------------------

Now in regards to the article I'm writing, welllll honestly I haven't really started it haha and who knows if I actually will. Probably. If I do it won't be any super advanced stuff.
It will just be basic principles, general descriptions of what they are, and how they apply to tricking. What I'm going to do is divide it into sections per each topic. Having the practicality or general "layman's" term of each subject explain up front, and if one so desires they can read the more 'scientific' principles behind it.
Like you said it probably will be able to be understood by 7th graders haha, well ok maybe late high school. The whole thing about quality teaching is that it should be understandable by "uneducated" (hate that term) and "educated" (hate that term much more haha) people, with lots of simply terms and easy explanations.
That's why I'm trying to simplify my exposition a bit when I type now, because when a teacher uses a bunch of huge terms or tries to sound very knowledgeable by using a 'sophisticated' vernacular, that just shows that they're insecure and dumb haha. Good teachers can make complex things understandable very simply. In fact that's why I'm redesigning my whole site haha, among other things.

It's not going to be a revolutionary (or even important) article by any means. Nothing special.

[shengoikee]

haha that's a shitload of text

[Skilzat85X]

I was typing in the quick reply box, and yeno it takes a couple seconds to load your post before it gets added into the thread. So I'm sitting here like "hmmm i'm hoping that wasn't too long it seems ok *post pops up* OH GAWD NOOO".

[shengoikee]

droppin science yo

[tigtricker]

skilz is your physics knowledge self-taught? can you do maths haha? treat us like a rigid body (for rotations)! think about if we were a cylinder rotating. then compare with a similar cylinder with a larger radius and maybe this will go some way to answering your arm problem!

also if you want to get carried away you could think about the effect of moving your arms from out to in.

[Skilzat85X]

Yes yes I know about the difference the larger radius makes and no I'm not self taught.
The problem with treating us like a cylinder is we aren't a cylinder, haha. We're made up of a bunch of parts, and in many (most) situations these parts are not rigid.

[A_Wilhelm]

another idea for the rotation speed thingie with arms out vs arms in (torquing) is, that the force needed to let the body rotate that fast isn't even created, becasue by just pulling your shoulders around you can create much less force compared to wrapping your arms in in a circular motion, at whichs end the impulse of the arms is being passed to the body.

Atleast when you mean that the arms are doing nothing. if they would still pull around, and quickly stop at one point to pass there impulse to the body, it would be nearly the same (dependent on how far they pulled before they stopped, how quickly the stop etc)

But you were speaking of a situation in which the body is already spinning, so this is just an additional thought, which is way more realistic though, because when you've already pulled your arms in, you wont put them out again for no reason. and a body doesn't start rotation without a reason either.

[Skilzat85X]

Your body leaves the ground rotating, it does this by pivoting while jumping. Therefore, upon entering the jump there is rotational velocity without the arms having to be wrapped. Due to the frictional force of the ground on the person, the ground now acts as a 'pivot point', so a person can generate a torque on themselves using other parts of their body, usually the core. It is perfectly possible to leave the ground with your arms wide out and flying while still having rotational velocity upon entering the air.
Examples: Pop tricks, cheat tricks, heck almost any trick other than straight back or straight forward ones. (I should have noted in my previous point that the scenario I'm talking about is referring to a person who is in the air with their arms already out, with or without rotational velocity. It's one of those hypothetical 'in a vacuum' type presentations lol)

Technically, the act of wrapping the arms does not generate a rotational force, it simply decreases the moment of inertia, which can increase the speed your rotating without needing to exert a torque.

However, the arms/shoulders still can exert a toruqe on the body in the air. Case in point: flash fulls, x fulls, delayed fulls, etc. Of course there is always more than just the arms and shoulders involved, however I'm using them in this example because they are able (because of their mechanics) to generate a force aaand because they're the most obvious part of the body that can be used to increase the moment of inertia.

[EmpRitz]

Physics is the study of motion. Tricking is motion, ergo physics applies to tricks...


Physics is the reason tricks work the way you do. (As well as the reason, you can walk, breathe, eat, go pee etc etc). Many great tricksters don't know anything about physics, but an understand of how motion works will only benefit your tricking at any level. Im my experience, teaching and learning tricks is much more effective if you understand the physics behind it. It is much easier to visualize (with vectors et al).

And Skillz MAKE THE ARTICLE, it will be great. More knowledge=better tricking

*two thumbs up to Skillz for this thread*

[dpitlock]

This is all retarded.

[dpitlock]

Do what you want, but trial and error is the better way.

[Source]

Why is trial and error the 'better way'? Really. Why?

[dpitlock]

You can analyze all you want, but you will never know until you try.

[dpitlock]

You can think about the science of tricking. But, trying to figure out the physics so you can do the trick better or do the trick at all is retarded.

Look at every good trickster. They try until they get it.

[Skilzat85X]

Dan man you're so incredibly sexy sometimes! You haven't even read the thread have you? We already talked about this a few pages ago and came to the exact same conclusion my love!

[dpitlock]

I never read anything you write because you spend to much time writing and less time going out and tricking.

[dpitlock]

Nice edit. <3

[DYoo]

lol i love dan.

[tigtricker]

lol dan skilz already had this exact discussion with kyle. nobody cares if this helps our tricking. we are not substituting tricking time with physics time.

Skilz the cylinder thing was getting at actually looking at how significant the effect of moment of inertia is. it is mahussive, and definitely the reason that having your arms in makes you spin faster! if you can you should manufacture this experiment: get some retarded kind of turntable thing that you can stand on. holding like a litre of water in each hand get someone to spin you with them out then hold them in, or the other way around. obviously the water amplifies the effect, but it is suprising just how you can have someone barely noticably moving with arms out, then without applying any new force, but just adjusting their moment of inertia, they are spinning pretty uber fast.

I think you already answered your own question anyway haha.

[tigtricker]

Technically, the act of wrapping the arms does not generate a rotational force, it simply decreases the moment of inertia, which can increase the speed your rotating without needing to exert a torque.

However, the arms/shoulders still can exert a toruqe on the body in the air. Case in point: flash fulls, x fulls, delayed fulls, etc. Of course there is always more than just the arms and shoulders involved, however I'm using them in this example because they are able (because of their mechanics) to generate a force aaand because they're the most obvious part of the body that can be used to increase the moment of inertia.

ok i just read this and this is exactly my thoughts haha.

interestingly though on the flash full thing you could probably do it without any torque still but just slowing yourself wayyy down with moment of inertia adjustment then readjusting to accelerate for second spinning phase. But yea i totally agree with this quote as the "jist of it".

[dpitlock]

lol dan skilz already had this exact discussion with kyle. nobody cares if this helps our tricking. we are not substituting tricking time with physics time.


I see this now. I guess I have to start reading other peoples post huh

EDIT: ARGHHHHH RAHADANDAKJ
UMMM... WELL... GO TALK YOUR MUMBO JUMBO ON PHYSICSTUTORIALS.COM/FORUM AND STOP TAINTING MY TRICKING WEBSITE.

[Skilzat85X]

UMMM... WELL... GO TALK YOUR MUMBO JUMBO ON PHYSICSTUTORIALS.COM/FORUM AND STOP TAINTING MY TRICKING WEBSITE.
Ahahahah! <33

[Ambitrixterous]

There is a lot of talk in this thread about the knowledge of the physics behind your tricking being useful vs. being purely for the sake of knowing, and I will say this:

-I can only do what I do because I know what I'm doing

Does that mean everyone must know the workings of their movements in order to perform them? Hell no, in my opinion 99% of trickers do not in fact understand the actuality behind their tricks in the slightest and obviously we have a lot of good trickers out there...

What this DOES mean is that if you can grasp the truth of these concepts in its entirety you will only be limited by your proper application of them & the physical limitations of your own body.


i thought that you made a comment on the video of the guy doing full one way and then back the other is an example of what Source was saying.

You are absolutely right about this; when I am wrong I fully admit it. In this case I had confused motion with directional velocity (and let's be fair, this was a pretty crazy trick/example so it was an easy mistake to make) and came out on the wrong side of the issue. The MOMENTUM never ceases while the velocity is redirected during the trick (:good: physics)


So onto the issue at hand, if thinking about your tricks is boring & you find repetition as your best weapon, then by all means disregard the idea and practice what works best for you. Kudos on being naturally talented to the degree that you can learn without!

If you find the science behind the moves intriguing, then apply it in various ways and see what works and what turns out to be bullshit, simply talking about it in theory IS only for your own knowledge. Take those theories and test them in the field, like a real scientist!

:wise::square::vampire:

[tigtricker]

There is a lot of talk in this thread about the knowledge of the physics behind your tricking being useful vs. being purely for the sake of knowing, and I will say this:

-I can only do what I do because I know what I'm doing

Does that mean everyone must know the workings of their movements in order to perform them? Hell no, in my opinion 99% of trickers do not in fact understand the actuality behind their tricks in the slightest and obviously we have a lot of good trickers out there...

What this DOES mean is that if you can grasp the truth of these concepts in its entirety you will only be limited by your proper application of them & the physical limitations of your own body.




You are absolutely right about this; when I am wrong I fully admit it. In this case I had confused motion with directional velocity (and let's be fair, this was a pretty crazy trick/example so it was an easy mistake to make) and came out on the wrong side of the issue. The MOMENTUM never ceases while the velocity is redirected during the trick (:good: physics)


So onto the issue at hand, if thinking about your tricks is boring & you find repetition as your best weapon, then by all means disregard the idea and practice what works best for you. Kudos on being naturally talented to the degree that you can learn without!

If you find the science behind the moves intriguing, then apply it in various ways and see what works and what turns out to be bullshit, simply talking about it in theory IS only for your own knowledge. Take those theories and test them in the field, like a real scientist!

:wise::square::vampire:

aha this is an excellent post in many ways :cool:

EDIT: if only i could apply my (limited) understanding more effectively :worry::ouch:

[Alexx]

dan teach tig to cork !!

[BrandonLenz]

Eliminate resistance on the axis of rotation. That's the only physics I have to remind myself about when I trick.
this is exactly what I tried to tell skilz a while back, and he simply said I was wrong.

[Skilzat85X]

Show me the topic (cause I don't remember haha) because I'm sure you either said something wrong or just worded yourself terribly, or used a scenario in which this principle didn't apply, etc.

EDIT: Ooooh I remember why.

You weren't saying anything about eliminating resistance on the axis of rotation. What you said was:
Shorter and buffer = better flipping
Tallish and lean = better twisting.
It's all about centripetal motion of the body's rotation along an axis.
And of course I still hold the above statement to be BS since there's an infinite amount of other variables involved in flipping and twisting obvs.
To which I said:
Without googling, please give us your definition of "centripetal motion of the body's rotation along an axis", pleeeease.
To which you said something completely ridiculous like:
haha why? I am in the International Baccalaureate Program taking Physics Higher level at an international school. its like 2x AP physics high.

i'm not just a stupid noob that usually pops up and starts talking shit. although i dont know alot, we have recently been studying Aristotle's physics laws, and Newton's laws aswell, hence me talking about centripetal forces and motion.
Its actually highly interesting, i recommend everyone to read Mr. Isaac Newton's Mathematica.
To which k-slash soo appropriately said:
You didn't answer his question, you just avoided the subject and put in additional information to make yourself seem like you knew the answer.
To which you said something completely random like:
i was slightly offended by skilzat's instant classification of me, so i decided to tell him a bit about why i am allowed to say stuff like that, he isnt the only person with some sense on these forums u know? haha
To which I quite appropriately responded:


I didn't ask you (Brandon) to tell me what school you're going to and how you're destined to become the next major physicist, what I am asking now is to define your usage of "centripetal motion of the body's rotation along an axis", what it means in tricking practicality, and foremost, how it proves that "Shorter and buffer = better flipping; Tallish and lean = better twisting."
And then heck just read the rest of the thread ya mugs!
http://www.trickstutorials.com/forum/showthread.php?t=56237&page=8

The point is you made an incorrect statement and I said it was wrong, and then you went off on some huge tangents which weren't even related to your initial point combined with more trying to gain credit by rattling off credentials.

Basically, here's how it went:

Brandon: "Shorter and buffer = better flipping; Tallish and lean = better twisting."
Skilz: Without googling, please give us your definition of "centripetal motion of the body's rotation along an axis", pleeeease.
Brandon: What skilz whaat I know all about physics i'm in a class for extra smart people you all are just pawns in a much larger game.
Skilz: Umm I just asked you to define it.
Brandon: Why skilz why no you're wrong skilz. Do you know why? It's all about physics. Gravity man gravity.
Skilz: What the nigg does that have to do with short people being good at flipping and tall people being good at twisting.
Brandon: no skilz you just hate me no

[BrandonLenz]

Show me the topic (cause I don't remember haha) because I'm sure you either said something wrong or just worded yourself terribly, or used a scenario in which this principle didn't apply, etc.

EDIT: Ooooh I remember why.

You weren't saying anything about eliminating resistance on the axis of rotation. What you said was:

And of course I still hold the above statement to be BS since there's an infinite amount of other variables involved in flipping and twisting obvs.
To which I said:

To which you said something completely ridiculous like:

To which k-slash soo appropriately said:

To which you said something completely random like:

To which I quite appropriately responded:

And then heck just read the rest of the thread ya mugs!
http://www.trickstutorials.com/forum/showthread.php?t=56237&page=8

The point is you made an incorrect statement and I said it was wrong, and then you went off on some huge tangents which weren't even related to your initial point combined with more trying to gain credit by rattling off credentials.

Basically, here's how it went:

Brandon: "Shorter and buffer = better flipping; Tallish and lean = better twisting."
Skilz: Without googling, please give us your definition of "centripetal motion of the body's rotation along an axis", pleeeease.
Brandon: What skilz whaat I know all about physics i'm in a class for extra smart people you all are just pawns in a much larger game.
Skilz: Umm I just asked you to define it.
Brandon: Why skilz why no you're wrong skilz. Do you know why? It's all about physics. Gravity man gravity.
Skilz: What the nigg does that have to do with short people being good at flipping and tall people being good at twisting.
Brandon: no skilz you just hate me no

you do just hate me i knew it! i also hate internet arguing, its laborious, so no comeback here.


EDIT: firefox wants me to capitalize internet??? helll no.

[simon]

you do just hate me i knew it! i also hate internet arguing, its laborious, so no comeback here.


EDIT: firefox wants me to capitalize internet??? helll no.

dont be a bitch brandon.jeez.

[Adam Ross]

If i met skilzat.
Tay Zonday would tell me i got his name wrong.

[Skilzat85X]

Don't feel the need to reply to this or anything I'm just posting it cause it was an admittedly awesome post and took forever to make and I'm deleting the thread it was originally in.

Well then, I don't want to disappoint. :wink:

The point of a round off in terms of gaining height is to transfer kinetic energy into gravitational potential energy. (Alternatively, you could say it's turning momentum in the direction parallel to the ground to momentum perpendicular to the ground).

Assuming that we manage to do this 100%, that means that...
mgh[1] = ½mv²[2]
gh = ½v²[3]
9.8[4]h = ½v²
h = (½v²)/9.8

The only independent variable here is v, which means that the height we get by converting kinetic energy into gravitational potential energy is directly proportional to the velocity we enter with. So let's say you run into the trick at 6m/s, if you could perfectly (that is to say, without loosing energy as heat, to deformation, etc), your center of gravity (usually around 1m off the ground at standing) would get up to a height of another 1.8m off the ground.
Of course, you're always going to loose some kinetic energy (since these are in fact inelastic collisions) as it's converted to other forms during the course of the trick, so the actual GPE gained is only going to be a certain percentage of the result of the equation. But that's negligible to the principle.

This isn't just equations though, to produce the result of the equation, one must execute the proper technique to convert kinetic energy into GPE.


So where the nigg does arms in a roundoff come into all of this.

Because arm technique in a roundoff effects how much kinetic energy is lost when you're doing the technique. Since K = ½mv², v = √((2K)/m), meaning if we have a certain amount of kinetic energy, we can deduce the velocity from this. And lowering the kinetic energy will result in a lower velocity. And as we proved earlier, less velocity means less height.

How do we lose kinetic energy?

Because bending the arms into the ground decreases the amount of momentum, and thus kinetic energy[5] we have, which decreases our velocity...and well you know the rest.
Why? Because bending our arms and lowering our upper bodies to the ground, and then throwing our upper bodies, increases the time it takes for the feet to reach back to the ground and launch us up into the air.
By Newton's second law, net force equals a change in momentum divided by the time taken (Fnet = (∆mv)/(∆t)). So the more time taken means a smaller force. It also decreases the amount of distance you can cover in your roundoff.
And, a change in kinetic energy requires work, since we're changing it to GPE (or basically, increasing it again, but with a different direction [of momentum, since energy is scalar]). (Work) W = F x d, and W = ∆K too . So the less force we have (which is lowered due to the greater amount of time it takes), the less work we do (not to mention the less distance we cover, but that's negligible in dealing with this principle), which means the less kinetic energy we have to be able to convert to potential energy by the technique.

----------------------------------
[1] GPE (Gravitational Potential Energy) = mgh (Mass * Gravitational Acceleration * Height)
[2] K (Kinetic Energy) = ½mv² (One-Half * Mass * [Velocity Squared])
[3] We can eliminate g here since it's equivalent in both sides of the equation, same principle as dividing by 1.
[4] 9.8m/s² is acceleration due to gravity, g.
[5] Can't be bothered to write out the proof for this lol.
----------------------------------

Hmm I have a feeling some of my specific mathematics could be wrong (though the end result is correct of course), so I'll read over this again later and make sure.

In Conclusion:
Bending the arms absorbs kinetic energy, primarily by increasing the time taken it takes to change the momentum, resulting in less force, less work, and less GPE generated by the technique.
However, as one can notice by the above equations, namely (Fnet = (∆mv)/(∆t)), individuals can still increase the momentum, kinetic energy, work, and all of that by compensating for the increase in time, or ∆t. Namely, by "muscling" the trick to "unnaturally" decrease the time it takes for their feet to go from the ground back to the ground, thus making the technique still plausible if one exerts more energy when doing the technique, but also makes it very much less efficient.
Does it matter? Not really, haha. Is it still incorrect to assume that bending the arms can result in more height out of the technique? Yes.

But skilz but skilz, what about the force generated by pushing with the arms?
Well it may make you feel good and all that, but in terms of helping assist with the 'jump' of the trick, it's relatively negligible, since the force of the push is not in the same direction as the jump, therefore, only the component of the force which is parallel to the direction of the jump will have any effect, not to mention that arm muscles are not really designed to generate that much power anyways, so it'd be a nominal force regardless.

----------------------------------

(Just a side note) By the way, this principle also proves that all this "you block on aerials and btwists and raizes" and all that is BS. The purpose of blocking isn't to jump per se, it's to convert KE into GPE, and when one bends down to prepare for a jump, as they do in Aerials, Raizes, Btwists, etc etc, they're increasing the time it takes to change their momentum, therefore loosing momentum and kinetic energy, and if something vital to the technique, the digging down part, results almost intentionally in a loss of kinetic energy, how could it possibly be designed to convert such energy into gravitational potential energy?
Height in those tricks is generated by the force of the jump into to the ground which is generated by contraction of the muscles, not by blocking. This isn't to say greater momentum won't help them, though, but it isn't blocking momentum or energy.



(I have a physics exam tomorrow, so this is my equivalent of studying for parts of it, haha. :smile:)

[jan]

I thought that to do a twist, all you had to do was to jump... and twist... And not slack off in midair.


Velocity squared, people.