Very interesting take on Electrodynamics. Typically, the electric field and the material relations are just thrown out there at the boundary between materials and the reader/audience is supposed to figure out what displacement field and polarization actually mean. I think this way provides a more holistic view which THEN culminates into the electric field at the boundary so kind of the other way around but much better. Thank you for this!
Thanks for your comment - I am always looking for ways to explain things more intuitively and happy to hear that it seems to have worked on this occasion!
Sir why haven't you uploaded in long time ? Also can you make some videos on statistical mechanics from scratch as I trued to understand the Maxwell boltzmann distribution but couldn't find any good video with derivation :(
Sir I have a few unrelated questions 1) why do we assume that tension in a string is constant along the entire string 2) why is rotational kinetic energy 1/2Iw^2
1) Apply F = ma to an infinitesimal element of the string, and you get T₂ - T₁ = dm × a, where T₁ and T₂ are the tension forces pulling the element in two opposite directions. We often assume that dm = 0, which implies that T₂ = T₁, hence the tension is constant along the string. The result only holds if the string is either massless or not accelerating (or both), and assumes that no other forces (e.g. friction) act along the string. For an example of non-constant tension see my old video on the capstan equation: ruclips.net/video/T4wVlOYFoH8/видео.html 2) Summing the kinetic energies of all particles in a rigid body gives: Σ½mv² = Σ½m(rω)² = ½ × Σmr² × ω² = ½Iω², where the final step follows from the definition of I.
@@DrBenYelverton sir I have an idea for video , you can make a video on solving JEE advanced or mains problem using different ways (like using lagrangian and Newtonian both) this would get a lot of views too as JEE is pretty popular amongst Indian students :)
Well, arguably finding the E field is the ultimate goal; it's more fundamental in the sense that E is what determines the force on a charged particle (via F = qE). The D field is not actually necessary at all, and Maxwell's equations are complete even if written only in terms of E. Taking this viewpoint, D is just a quantity that's introduced to make it easier to find E when there are dielectric materials involved. As @mingmiao364 mentioned, I have a couple of other recent videos explaining why exactly D can be sometimes be more convenient to work with.
Can't wait to see a series on the H field too!
Glad to hear it! That will probably be coming early next year.
Very interesting take on Electrodynamics. Typically, the electric field and the material relations are just thrown out there at the boundary between materials and the reader/audience is supposed to figure out what displacement field and polarization actually mean. I think this way provides a more holistic view which THEN culminates into the electric field at the boundary so kind of the other way around but much better. Thank you for this!
Thanks for your comment - I am always looking for ways to explain things more intuitively and happy to hear that it seems to have worked on this occasion!
Sir why haven't you uploaded in long time ?
Also can you make some videos on statistical mechanics from scratch as I trued to understand the Maxwell boltzmann distribution but couldn't find any good video with derivation :(
Just taking a short break over Christmas, I will be back soon! Will make sure to cover some statistical mechanics next year.
@@DrBenYelverton ok I will think of some suggestions by the time 😃
Sir I have a few unrelated questions
1) why do we assume that tension in a string is constant along the entire string
2) why is rotational kinetic energy 1/2Iw^2
1) Apply F = ma to an infinitesimal element of the string, and you get T₂ - T₁ = dm × a, where T₁ and T₂ are the tension forces pulling the element in two opposite directions. We often assume that dm = 0, which implies that T₂ = T₁, hence the tension is constant along the string. The result only holds if the string is either massless or not accelerating (or both), and assumes that no other forces (e.g. friction) act along the string. For an example of non-constant tension see my old video on the capstan equation: ruclips.net/video/T4wVlOYFoH8/видео.html
2) Summing the kinetic energies of all particles in a rigid body gives: Σ½mv² = Σ½m(rω)² = ½ × Σmr² × ω² = ½Iω², where the final step follows from the definition of I.
@@DrBenYelverton thank you sir 😀
@@DrBenYelverton sir I have an idea for video , you can make a video on solving JEE advanced or mains problem using different ways (like using lagrangian and Newtonian both) this would get a lot of views too as JEE is pretty popular amongst Indian students :)
And the problems are also great for solving. (But they are usually numericals so you could also try to generalize the solution)
A few people have suggested this, I will have to take a look at some of the papers some time!
What are the uses of the D field?
It shows up in the Maxwell equation and is a convenient way to describle electric field within matter. See the latest 4 videos for more explanation
Well, arguably finding the E field is the ultimate goal; it's more fundamental in the sense that E is what determines the force on a charged particle (via F = qE). The D field is not actually necessary at all, and Maxwell's equations are complete even if written only in terms of E. Taking this viewpoint, D is just a quantity that's introduced to make it easier to find E when there are dielectric materials involved. As @mingmiao364 mentioned, I have a couple of other recent videos explaining why exactly D can be sometimes be more convenient to work with.
@@DrBenYelverton ah ok thanks, I will check those out