What Is The Magnus Force?
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- Опубліковано 24 сер 2024
- Whenever an object spins through the air it experiences a 'Magnus Force' due to friction between the air and the object's surface. This force was originally identified while studying the trajectories of cannon balls (though earlier observations of this effect exist). The Magnus force is essential in most ball sports including golf, cricket, tennis, and baseball.
At the end the ball demonstrations were conducted with a 100 mm diam polystyrene ball and the launcher was made by bending a long, thin, aluminum rod and bolting the ends to a block of wood as a handle.
Music was provided by Kevin McLeod (incompetech.com) Scissors and a stock clip from FCP.
"Do not assume air resistance is negligible."
He is speaking the language of the gods...
I see that we have a spin user here
Coen Ruluked we know everyone’s here to learn the principles of spin and the golden rectangle
People have survived falling out of airplanes with no parachutes due to air resistance. The upward force of air particles colliding with their body reaches equilibrium with the (roughly) constant downward force of gravity, which causes the falling body to stop accelerating towards the surface of the earth and instead reach a terminal velocity of only around 120 mph which SOMEHOW A PERSON CAN SURVIVE (not likely though) which must be a truly RELIGIOUS experience
@@Twelvehourpowernap 😨😨😨😰😰
Ah, air resistance, the so ignored phenomenon in physics. But magnus effect gives it life.
Haha if you think it's ignored you haven't been doing good questions. It's basically exactly the same as stokes law
The Magnus Force is the force by which you get steamrolled when your name is Ian Nepomniachtchi and you play in the Chess World Championship.
Was looking for this❤😅😅
This is the kind of Physics I'm actually interested in
me too
Me too
Same
Assuming ideal cases each time in physics is just not what I wanted
@@studywithme-z get rekt
@@studywithme-z get booped on mate
"In chess"
When opponent is sitting right in front of world champ magnus carlsen they experience an absurd amount of mental force and that's what is called MAGNUS force.
This really explains the trajectory of top spin loops and chops in table tennis
The Magnus effect......we study that in 11th grade as a part of fluid dynamics here in india
?
that topic bought me here
I'm in 11 th and finals are beginning soon , 😬
Is it in did you know like stuff??
I’m studying aerodynamic and my teacher is from india haha
@scoutmasterkb28 you could think about Bernoulli's in the region immediately surrounding the ball in which case you would say the faster moving air on one side (in the example it would be on top) results in lower pressure than on the other side so this difference in pressure puts a force on the ball - so this is a valid explanation.
U inspire me a lot and I have also started my science youtube channel
ua-cam.com/video/HT2sBTbxyQc/v-deo.html
Thank you. That’s what l was thinking
i still don't understand the science behind people disliking these videos. who are they? seriously.
Nilesh Suman haha
I think they tried and failed
They think balls are flat
Mentals
And if he turns his head sideways the air will go in one ear and out the other.
libtards lol its racist
Great discussion. I first saw the magnus effect demonstrated in a fluids lab in 1966 when we took our first trip to third year fluids lab. We had pressure tabs around the cylinder and measured the pressure around a rotating cylinder in a modest size wind tunnel. There is a nice CFD simulation on UA-cam which animates this effect in color.
Liked the professors talk.
@someblokecalleddave1 the cricket ball has another force on it due to the seam, or later in the game due to the roughness of one side. This causes the ball to swing toward the rough side. An episode on this is coming up soon.
@veritasium I would be very interested in your take on another cricket ball 'phenomenon' known as reverse swing. Where, in theory, the polished shiny side gets heavier from spit saturation and causes the ball to now swing the other way. Cricket commentators have lots of theories, but rarely grounded in science.
A bit mistake here maybe. I think the ball swings to its shiny side when its old, this phenomena is called the reverse swing. Bowlers like waqar younis, wasim akram and james anderson are few of the masters of this art
Excellent illustration! I had no idea the paper tube would be so illustrative. Great job!
@scoutmasterkb28 Nope! It's not to do with Bernoulli's because that considers only pressure, gravitational energy and translational kinetic energy, not rotational energy.
Its a shame this isn't taught in youth sports more. I spent hundreds of hours trying to figure out to manipulate a soccer ball and this never crossed my mind. This knowledge seems pretty necessary to making accurate free kick shots.
Roberto Carlos free-kick = Magnus Force
that's the first thing it came to my mind.
Rivelenio inspired Roberto Carlos, and he said it in an interview in world cup in brazil. Rivelenio did it in the 70 when balls were very heavy .. and harder to hit!!
I took a class on fluid flows and we briefly covered the Magnus Effect. I found slides from one of my lectures that the force had to do with differences in pressures on the top of the ball vs the bottom as it moves through the air. Others have already pointed this out, but to reiterate perhaps in a different way; as the ball moves through the air horizontally air is passes around the top most point and bottom most point of the ball equally. Lets say you hit a topspin shot in tennis. The ball moves through the air and on the bottom of the ball the fuzz(friction) on the ball is grabbing the air and moving it faster. On the top of the ball the friction between the ball and the air is grabbing the air and throwing it against the oncoming air wizzing past the ball. As velocity increases pressure decreases and you have a situation where high velocity but low pressure is on the bottom of the ball and higher pressure low air velocity is on the top. The atmosphere presses down on the ball towards the low pressure causing the ball to accelerate towards the court faster than it normally would with just gravity. The surface of the ball and the speed can also effect if the flow around the ball making it laminar or turbulent which when combined with spin can have some interesting effects. What makes golf balls and table tennis balls different is a good example of that. One other note that most people probably caught but anyways in the video it wasn't really explained why the cylinder moves backwards after being dropped from the plank. It's be cause the body is not moving through the air horizontally but on a diagonal initially so the fastest air relative to the cylinder is on the edge that just left the plank which caused the Magnus force to push down and back + drag as well.
I recently started playing tennis, and i was wondering about the effect of topspin on trajectory.. Exactly what I thought! Thanks a lot !!
That paper cylinder demonstration is fantastic!
I am SO glad I subbed to you. I'm so delighted every time you post. I like learning all these wonderful things you show. Thank you so much!
Very well presented, your partner is quite clear headed and clearly spoken as well!
That's why table tennis is such an awesome sport. You witness all types of physics if you induce spin on the ball, making the game more interesting.
fun little trivia, the mangus effect airflow is some what equivalent to an airflow around an airfoil. In fact, in the ye olde day before computer was powerful enough to handle CFD, people used to calculate theoretical lift of an airfoil by using conformal transformation of a spinning cylinder model.
There were attempts to utilize this effect to create VTOL/STOL aircraft, unfortunately the added weight exceed the added lift. So these projects were scrapped
@vsr600 No, I don't think so - just two ways of thinking about the same thing...
If you play any ball sport,this is either common knowledge or cool tricks that happen but you don't understand.
I never understood the science behind the curve ball. Until now.
That's a nice way to show the effect of the Magnus force. I think I'll use that little experiment to demonstrate it in the future.
please elaborate on this. The paintball players of the world would love to hear about objects spinning through the air. This affects their game then any other sport!
Reading a lot of comments. It’s crazy to me how bad my school system was in America. It makes sense that I flunked out of college, for most people those intro bio and chem and physics courses were review but dude I didn’t learn anything in high school. I slept through my classes, got straight A’s, graduated top 5 in my school. But came out academically anemic
I'm expecting a video on balls with seams
that's amazing :)
Nine years ago.
Nine likes.
Top comment.
i am a formula one fan and i always knew about the upside down wing to give the cars more traction, but i never thought about the actual wheels giving the car more traction (downforce). very interesting.
What a clear explanation! That gent is really clever!
This "Magnus Effect" it just a principle of pressure difference. where the airflow is higher the pressure on that spot is lower, and therefore, the object has the tedency to move towards that direction.
Yeah it makes sense. My brain is struggling with the fact that the velocity on both sides of the spinning "ball" is equal. Therefore both should be low pressure equally relative to the perpendicular direction of travel. I know theres a piece of physics I haven't grasped yet, though.
@@richis2fast4u I am no expert, but I guess it is not the same speed because of relative speed, like the both "sides" of a wheel while a vehicle is moving. The ball was moving to the left and rotating clockwise, so the "top" point of the ball had a relative speed vector of the ball speed to the left - linear speed due to the clockwise movement. The "bottom" point had a relative speed of the ball speed to the left + linear speed due to clockwise movement.
@@richis2fast4u Well, in physics we say the speed to both sides of the ball is equal "at infinite", that is, far away from the ball. When studying cases like this, it's fundamental to look at what's happening near the ball, at the distances in which the velocity field is very distorted and the speeds at both sides of the ball are different from one another.
goo.gl/images/i9hfRV
You could find cases in which the velocity field is symmetrical, for example if the ball wasn't spinning, the speeds at both sides of the ball would be identical even very near the ball, and it would look kinda like this:
goo.gl/images/3JNyEQ
In this case the ball wouldn't feel any force perpendicular to the direction of it's flow, of course it would steel feel the drag.
TheMoviemax12 thats bournouli, magnis just utilizes it
Through my 85 years on this earth I always believed that the electron in conductors placed in elect5ric or magnetic field as in generators, motors, transformers and other electromagnetic products as an antenna etc there is an Electromagnetic Magnus effect on the charged spinning electron and what I have done up to know seem to explain all the behaviour of static and moving electrons in electric and magnetic fields.
I like this better than the relativity proposals where the high speed charges will become more dense and so act as charged up conductors.
It is an interesting postulate to use Magnus effects on spinning and moving and spinning charged electrons . I hope to publish all this when I find that all fits well and the Electromagnetic Magnus effect explain all there is in James Maxwell Equations.
if you make the direction in which the paper flies your x axis it will fly downwards ^^
Air friction slows the paper down, gravity still acts whilst the initial inertia (received through the board) fades over time. thus the direction the paper takes ist straight down to begin with, now magnus force steps in and pulls it "backwards"
Hi! The experience with the paper cylinder just baffled my students. We compared the cylinder's motion with that of a plastic tube of exactly the same size (by rolling the paper over the plastic tube in the first place).
Thanks for these inspiring videos with Rod Cross!
Btw, 2 small misprints in your introduction text:
experience -> experiences
ealier -> earlier
Are you an english or a science teacher LOL
For example, the cylinder is not only moving downwards with gravity, it its also rotating. The rotation moves the air, applying the phenomenon seen in the basic graph at 02:00.
The force always acts perpendicularly to the actual movement of the roundish object, which means that the cylinder will actually move backwards.
This is easily demonstrated at home using a ruler. The effect of the spin is more pronounced than on a ball. It is also fun to try. Hold the middle of the ruler with the edges between you fingers and your thumb. As you throw the ruler let go with your thumb and pull back a bit with your fingers. It is possible to make the ruler loop around in the shape of a C.
@1veritasium I think you're alluding to seam bowling primarily, shutuprafa and I are more concerned with spin bowling which is far more complex as the seam isn't aligned in the direction of flight. The outcomes that we're interested in are 'Drift' and 'Dip'. Dips relatively straight forward, but drift is far more difficult to disect and make sense of - which is my objective.
Just started to , Think about this,,. The Magnus Effect. Learning, some thing , New .Thank You. GP.
I am regualar watcher of veritasium,but this is the first time i am viewing a video from veritasium because of a homework from my college
DO AN EPISODE ON HYDROGEN FUEL CELLS!
"The Magnus effect is often considered a demonstration of Bernoulli's principle, but this is incorrect, as the viscosity of the air - assumed to be negligible in Bernoulli's principle - is central to understanding the magnitude of the force." from wikipedia
Thiago's goal strike against Porto brought me here
I thought I was gonna have the original comment but well, you ruined that for me. Hope it makes you happy 😭
The swing from a cricket ball bowl is caused by the differences in texture between the left and half sides, in which one side is polished. Still caused by magnus force but not by ball rotation.
Dynamic lift
Dynamic lift can be defined as the as the motion of any object upward due to that two different type of motion one is rotational motion and address translational motion forward due to the due to the pressure gradient fluid around the object.
For example ball for example a cricket ball when it is thrown from the bowler hand to get the spinning so that is axis and translational motion towards the stamp so it get the lift where's the stamp to get them in Swing Out swing due to the dynamic lift. These things happen due to the surrounding air.
incredibly easy to understand.
It is because of a range of different reasons. First of all, the ball is more inert, which means that it requires a larger force to move. The magnus force is only so-so big in this case, and of course, the force will virtually have a larger effect on a lighter object than on a heavy one. Also, since the paper cylinder is larger, it will naturally create a larger force, hence moving more.
If a cylinder starts rotating clockwise, then at first it is surrounded by anti-clockwise vorticity. This diffuses outwards by the action of viscosity. If there is a crossflow over the cylinder, the anti-clockwise vorticity in the flow is then convected away, leaving the cylinder as a naked clockwise vortex. Bernoulli’s principle then produces a net transverse force, which is the Magnus Force.
Magnus force is to be reckoned with. Curve ball can be tricky.
Yeah, the Bernoulli's principle probably plays a part with deflecting the air flow, I don't really understand that part in the article, but the actual effect comes from the deflection and conservation of momentum.
Very Informative Thank you for posting, These are the videos that deserve more views.
@1veritasium Yes it does! air pressure is lower on the side of the ball /cylinder where the air velocity is greater; hence a side force.
Btw: "there's a force perpendicular to the spin axis" AND to the velocity of the centre of the ball.
Actually you are right and so are they. Bernoulli's principle and Newton's third law are different ways of describing momentum conservation. It's equivalent in this case.
Ya exactly what I thought. Ithink the boundary layer created by the ball is responsible for both of the effect, while the air on the top side is speeding up, it is also always being dragged downward hence the ball "pushes" itself upward.
That was a good shot/editing with the paper an the ball, simultaneously falling down. That was "aha" Moment. Thanks!
excellent demonstrations, didn't know any of this... we owe a lot to 18th century British mathematician Benjamin Robins who first discovered this with cannon balls. Forward, back and side spin...
will there be an episode about the reverse magnus effect?
I'm doing a project about this subject right now and this video really explains alot!
i hope there will be one about the reverse magnus effect soon.
thanks alot!
Bullets are only aerodynamic if they're flying pointy end first unlike spherical balls, which present the same profile no matter which way they are facing.
The spin creates a gyroscopic effect, which keeps the bullet from tumbling along its flight path, maintaining the bullet's aerodynamic profile and allowing straighter trajectories.
Interesting as he spins the paper cylinder and says "as it's spinning clockwise the force is down". It is clockwise from his perspective (holding the cylinder with his left hand and looking at the right side of the cylinder), but from our perspective (= the persepective of the camera), he is moving the cylinder in a counterclockwise direction. I think using clockwise/counterclockwise is not wise :) Much better to describe this in terms of topspin/backspin which are relative to the forward direction of the ball's trajectory rather than to one person's perspective.
I don't think that they are the same thing. With Bernoulli's principle, force is transferred through collisions (and lack thereof) with air particles.
The other force talked about was a deflection of the airstream; it transfers the force through friction.
I am under the impression that the Magnus force is a combination of the two. The slowing down of one side (increased pressure) combined with the speeding up (decreased pressure) and deflection of the other side combine to make the Magnus force.
Airsoft guns have an adjustable system called hop up which imparts backspin on the BBs, you can fine tune it to increase the range of the BBs.
Science bitches!
Why have they designed the gun to backspin anyway is it a safety feature or just a misconception on the designers side?
No... It's by design. You see how the magnus force causes the ball to curl through the air?
Well by applying that force to a BB as it's flying through the air towards a target you can adjust the amount of force applied so that instead of curling downwards as gravity takes hold of it, you can make it curl upwards, and if you tune it correctly, it just stays level.
You apply just enough to counteract the pull down from gravity, so you get it to fly straight for far, far longer, probably more than 4 or 5 times the range it would otherwise go.
Thank you thats quite interesting. Bullet4MyEnemy
I had an Idea that airsoft BBs would have their surface like golf ball. Maybe it would make them even more stable in the air?
I've thought about it before and looked into it; apparently it's been done before but the size of them makes it a negligible difference.
It also massively ups the production costs or something, so they were never put into production.
Wow what a neat demo. thanks for sharing that
excellent video with great visuals!
This is exactly how lift works on a wing, but instead of spinning it has an airfoil shape to get the circulation of the flow around it. The air travels faster over the top and slower along the bottom of an airfoil creating a circulation which results in lift.
One glitch... at 1:35 the professor describes clockwise spin but he turns the tube counterclockwise. Then he reverses it and describes clockwise but turns the tube counterclockwise.
I liked this video and particularly liked the title of Magnus Force ( 1:03 ) and the comparison of the two superimposed on each other ( 1:14 )
Here is easy explanation. Backspin. Air travels against the direction of ball flight. Air travels faster on the top (ball spins and air travels in the same direction), and slower on the bottom, so creates an upwards force on the ball.
Hasnt my man Newton discovered this first? Magnus deserves the name but the real OG is Isaac.
I heard that idea too. It's similar - imagine a ping pong ball spinning clockwise and moving left. Due to Magnus effect it will have a lift. Then imagine the same ball stationary and blow above it to the right - due to Bernulli principle pressure above the ball will be lower than below - we have the same lift!
Iv learnt this same effect but using the term low pressure on side opposing air flow and high pressure on same side as the ball moving the ball to direction of low pressure side oppside air flow.
Good video. I think this bit is surely not right, "An air current curving around the ball and going down helps to raise the ball, by every force has an equal and opposite". It is not the lifting force. Where the ball is rotating in opposition to the air current, the air pressure builds up and exerts a force.
That's just basics aerodynamics: lift and drag. Magnus effect itself is the effect that keeps a projectile on it's path since they're already spinning along the longitudinal axis.
That's what I was expecting to see here.
Marksmen also study this force because it has a great effect on bulets.
No, I don't think that's the case. If that were true, then the tennis ball at 2:00 would go down instead of up because the air on the bottom is moving faster relative to the surface of the ball than the air on the top. With the Magnus force, the air on the top is pulled down due friction between the ball and the air. Since the air is being deflected downward, the ball is being lifted upward. This is due to Newton's third law: for every action there is an equal and opposite reaction
So this is what explains the hop up in airsof!
The background music is... distracting me. I feel like they're about have passionate love on a veranda in the spotted plains of Central Africa. LOL
Hahaha, wouldn't have noticed that if you hadn't said it, but you're right!
The Magnus effect actually happens to bullets fired by snipers, snipers actually have to adjust their scopes to account for this when they shoot.
also ..they have to take in account wind ... gravity, coriolis effect bullet spin etc ... is not like the games
2:00 - this is unnecessarily complicated ; it is Bernoulli's Principle for fluid dynamics. A high speed current has lower pressure than it's surrounding and thus pulls objects towards it (e.g. spray water parallel to the shower curtain / blow air parallel over a sheet of paper / a sailboat hauling into the wind). A top spin ball is pulling / twisting the air downwards, making the air move faster below it than above it.
ua-cam.com/video/LpuBrf3zixE/v-deo.html
Your explanation is not correct. The real reason is that because one side of the ball pulls air, the pressure of the air decreases, while the other side of the ball blocks the air, so the air pressure increases.
Magnus the Magnificent Magnoceros! Cool to see a DotA 2 player here.
Check out Roberto Carlos's free kick against France.... there you'll see a great example of a sportsman taking advantage of Magnus Force. Its just amazing.
very similar to coanda effect. magnus force because of air surface friction, coanda air air.
I thought I didnt know what a magnus force was then when he showed the cylinder going backwards I was instantly reminded of that basketball dam experiment and soccer players
Tennis topspin can do some crazy spins.
After 6 moths of I learn mangnus effect finally thanks buddy
To affect the flight of a ball I gather sandpaper is a popular material in some quarters of the world.
Rod seems like a badass guy
Actually, I think it is wrong. If the ball has topspin on it, the upper surface of the ball will have a greater velocity relative to the air than the lower surface. Based on Bernoulli, this should create a low pressure zone ABOVE the ball, but we know that a topspin shot dives down rather than floats which would be predicted by this. please correct me if i'm wrong.
I have found a way to very graphically demonstrate this effect with a heavy, evenly pitted sphere (okay fine, it's a golf ball).
If you stand in the shallow end of a pool, or even at the side of a pool, and hold the golf ball in your hand, throwing it at the water should, logically, cause it to hit the water and sink. However, if you apply a topspin to the ball, it will penetrate the surface, then rapidly drive back up and out of the water, skimming across the top like a flat pebble.
In the summertime air affects balls in a cooling and soothing manner
Bernoulli's principle has very little to do with friction. It deals more with pressure.
This statement is incorrect as well: " 'Magnus Force' due to friction between the air and the object's surface".
Although I don't believe any have made it past prototypes or flying models, there have been several aircraft designs using this phenomenon, sometimes referred to as Flettner, or Magnus aircraft.
Wonderful explanation
clear explanation guys !!!!
And I believe that this is the exact scenario in nature ;rather than going with Bernoulli's equation,....pressure variations...(as some books suggest)
My name is Magnus :D
Hello
+Magnus Breinholt may the force be with you :P
LOL omg
Magnus Breinholt awesome name dude
Marry a force ...
Gotta love that force
I guess I have figured out the solution. The backward motion of the paper cone is also due to the magnus force. But this time we have to consider the velocity, air fiction vertically because the vertical velocity obtained from gravity is significant in the case of paper cone.
The force is strong with this one.
Awesome!!! I love figuring out how stuff like this works! One question though, is there a way this relates to the leading edge of an airplane wing? In my aerodynamics textbook it talks about Magnus force mixed with Bernoulli and Newton to make lift, but it doesn't really go into how the rotating cylinder through air relates to an aircraft wing moving through air. Thanks!!
I'm 8 years late but I'm confused on the same thing!
my books talk about the exact same thing
These two are following the social distancing very well before even exiting of covid