In french "kinetic energy" is "énergie cinétique". There is no "T" in that. But it could come from the word "travail" which means "work" in french.

In my first year in physics 1 course, my teacher tried to give an overview on Lagrangian Mechanics, but he used a lot math tools that i didn't know at the time, for exemple a Taylor Series with two variables. So, I don't need to say that i didn't get anything that he said. But your video can give a very good overview of Lagrangian for a first year!. Good Job! I want a Series!

Nice reintroduction to the Lagrangian - it's been 50 years since I played with this.

This is amazing man. I've always had a lot of problems with parametrization, and although that was not the core of the video you made me see it in a different way. Keep it up

Your teaching levels of physics is very good and it makes me to listen to your teaching

Thank you so much for posting this! The explanation is super clear and very helpful for me to understand this topic which is entirely new to me!

Nice introduction to LM ... An important point which was overlooked is the way in which LM can incorporate generalized forces (which would appear as extra terms in the E-L equation). Such forces must be taken into account when some physical forces acting on the system are not conservative (and therefore not expressible via potential energy). Such forces also are especially convenient/useful for assessing relevant constraint forces.

After watching you video, I felt Lagrangian mechanics is a very smart way to do it. This feeling is like there is a house, front door is closed. Backdoor is opened but people don't know there has a back door in this house. When try to open the door and into the house, Newtonian mechanics try very hard use force to breaching the door, and Lagrangian mechanics just into the house from back door.

Really cool! I'm planning on getting a Physics degree and this just keeps me motivated.

This is such a great breakdown of what's going on. I'm in a 700 level mechanics course and this is pretty much on par with what we've been reading (Goldstein)

should the y_double_dot on 10:37 be minus g because it is acting downwards or I am missing something

simple and easy to understand, thank you!!!!

I wonder sometimes, how can something be explained this good. Thanksssss

At 13:14, the derivative should be positive because you defined y as -l*cos(theta). Although it doesn't affect the result as you are squaring it later!

T can be calculated- using resolution of vectors resolute T in vectors components as Tcosx (theta=x) and Tsinx. Tcosx and mg gets neutralized and we are left with Tsinx. Since, bob is moving in circular trajectory it implies we can equate Tsinx= mR(dx/dt)^2 where R is radius Therefore,. T= mR(dx/dt)^2/sinx

Exceptional introduction- THANK YOU

Please keep making videos on Lagrangian mechanics 🙏

Extremely wonderful video 👏.

11:57 The Potential energy is mglsin theta since the restoring force is mg sine theta

Thank you so much 😘 From vietnam with love

Came here from the subreddit Awesome video, liked and subscribed

Mr physics explained make more video on Lagrangian principle it's so helpful for me👍🏻

Excellent straightforward explanation

This was a really good video, Physics is very interesting subject, although a little complicated.

This video is really helpful, but I think the diagram at 4:45 could use a redraw of sorts ;)

Thank u sir for this nice explanation 👍🏻👏🙏

In your final solution for the pendulum problem you have upper case L in the denominator. It should be lower case.

For people that can't simply get over using the equation without knowing where did it come from (god knows I can't), video from Eugen Khutoryansky gives a rather satisfying explanation of Euler-Lagrange equation derivation.

Very good explanation !!

This video was really helpful!

I can see this is a BIG DEAL!

How will we obtain the Lagragian for an object sliding under the influence of force 'F' on a frictional surface?

I just realized how important is this when I saw the "LAGRANGIAN" is so big. !

Thank you so much Sir for this wonderful video. I am starting this topic in my 1st year. It is very helpful .

Great video and great explanation!!! I'm becoming a fan.

T was chosen by the person who introduced the concept of kinetic energy. It stands for "translational" cause it's the energy of movement

i love this channel

nicely explained !

I like the introduction series

Great Videos keep it up!

Thanks for the super tutorial! (Last formular of the pendulum: instead of "L" should be "l" [length of pendulum])

Amazing intro to lagrangian.

This video deserves to be prefaced with links to the sources for related and assumed knowledge, so people can get the pre-requisite knowledge required to understand and appreciate this video.

Great one !!!

Aahh yeah this man needs more than just one like

Great content, thanks ☺️

Wow, u made it easier

It's been a long time since I studied multi variable calculus. Can you remind me why you can assume ydot doesn't depend on y? When taking the partial of ydot with respect to y my first thought is that ydot could possibly be equal to a function of y so I wouldn't assume the ydot term would be zero.

So simply explained thanks ❤️

AMAZING ! , SUSCRIBED INMEDIATLY

At time stamp 10:30, shouldn't it be mg = -my dot?

thanks for a great video!

Great video, helped a lot. Also, would you happen to know why we use T-U as the lagrangian? I can't seem to find a good answer anywhere

Great lecture!! Thanks

Thank you! Thank you!

Thank you so much

GOOD JOB with this movie... Now I will check with others u movies. Maybe this channel is worth to recommend to others. :-)

Mewton: force LaGrange: energy

Thank you so much ❤

excellent teaching sir. But just one doubt, in potential energy, for Y we have to substitute (l - l cos(theta)) right??

Great vid!

i have some doubt why we take the derivitive of the lagrangian function for the solutions ? and how does it work ?

Good video and great explanation.

Will it not be Theta double dot =- g sin Theta/ Lower case L rather than capital L in the denominator? Also del L/ Del theta dot is zero in the first term because Theta dot is a function of time and not Theta. Am I right?

Could you explain why L is defined as T - U? Also when you were doing the partials around @10:00, even though y dot and y are different variables, isn't y dot still dependent on y and vice versa? So if you are doing the partial of one variable, wouldn't the other be affected as well, in other words when you are doing the partial of y the y dot is moving and vice versa so that the results are not clean? Help me if I am over thinking or there is something to this.

9:49 why 1st term with dy/dt or T in L when we do partial derivative of L it was ignored. dy/dt can have y in the equation in general and in fact in gravitational scenario it did. Wonder.

This might be a dumb question because I don't get the part from 12:20. I know that kinetic energy is (m*x*^2)/2 from newtonian mechanics but did you add an *y* because there is also the y coordinate? Or, if there would be an Oxyz space would we have to add also an *z* over there?

Thank you sir

Not sure about the right hand plot at 5:39. S, as defined by the integral, is a just a constant for each path, since y is a function of t, and we are integrating wrt t. So any plot S should be against "path". How is that represented by the horizontal axis?

This is a really amazing video!. Actually I was a little bit confused in 13:11, why y' is d/dt(lcos(theta))? it shouldn't by d/dt(-lcos(theta))?

How does the problem change when you have a pendulum in 3D space? when I plug my z value in, is it also lcos(theta)(theta-dot)? Or would the angle be different when referring to z? And then how does that affect the rest of the process??

then what should be the equation on the motion of the ball?

Awesome video 😍

@ 10:36 its negative g. great video!

Thank u sir.

Thanks bro cool vid

12:05 Potential energy is not - mgl cos@ but mgl (1 - cos@)

The Langrangian is the excess of kinetic energy over the potential energy of a system. ref: Lanczos

At 17:19. Shouldn't it be -(g/l)*sin(theta) ... lower l as capital L is used as the Lagrangian?

Great! Where does it come from?

You legend

T stands for travaille i think. Which means work

That 'identical' caught me off guard.. 🤣🤣🤣

Ah yes I should clearly be learning this going to 10th grade

So cool

Nice Explanation

Should that derivative with respect y be my' * mdy'/dy - mg?

This is great! Thank you! Does someone learn this as an engineer? Because I study Civil but have never seen this.

Anyone can tell me the playlist? I want to watch the other examples. Thanks!

Kinetic energy translates to "énergie cinétique" in french, so the T probably doesn't come from there ^^

thanks!

Interesting problem at 4:45, looks very familiar...

didnt know cheatcode existed irl💀💀

best video

Very clear explanation of how to do problems using lagrangian dynamics, but I still wonder where it comes from. Why did someone define L=T-U in the first place, etc. Great video!

Travail = Work

Great explanation! I was trying to go through the code, and it generates just one of the two plots. Any chance you can post a link to the entire code with the two plots?

What courses in mathematics do I have to have in my body before going inside the famous Lagrangian? Somebody can explain?

i prefer bance newtons cradle at each instance practice problem sets never tried double pendulum other than upside down newtons cradle at inverse forces

I don't think the T has a particular meaning in french either...