Recent content by abhishekkgp

thank you so much papikoss. that was great help. :)

exactly what i wanted to say! to argue in favour of this consider a wire carrying CONSTANT CURRENT. its easy to see that the charge density inside the wire at any point is zero as div(E)=k*div(J) now div(E) is proportioanl to charge density and div(J) is zero as the current is steady as assumed...

well, it may be constant in general. in case of wire with conductivity sigma, there is electric field inside the wire( given by ohm's law).. although if the current is steady and the conductivity uniform the divergence of the electric field becomes ZERO. is the curl of electric field in this...

your question is very much my question. i expect that the electric field outside a current carrying(regardless of whether the current is steady or unsteady) must NOT be zero. this is because... let's assume the contrary... i.e. let's assume that there is no electric field outside a current...

i agree. in my post#6 i have said the same thing. internal work( work done by constraints) = external work( work done by applied or external forces). this is true for arbitrary displacements(not necessarily infinitesimals). but the problem is that in the lagrangian formalism we write that VW...

yes.. you are right.. but can you do it for the virtual work principal for EXTERNAL( or applied forces). have you read the lagrangian formalism( probably in your analytical mechanics course) ? also read post # 6.

here you have written that infinitesimals are not being avoided. you perhaps wanted to say that infinitesimals are not being used.

virtual work has been discussed many times in physics forums... i saw many threads but my query was not discussed there. i ll see the books you have stated( if i can download them) and then reply. the link to thread you have given... i had seen it before but there my question is not discussed.

even in the analytical mechanics text while doing the lagrangian formulation infinitesimals are extensively used in both of the two books i am reading. but it just doesn't feel right to equate an infinetesimal quantity to zero! some friend of mine told me that even the methods of 'non standard(...

i saw a text on "structural analysis". in the index i didnt find virtual work but 'virtual crack extension method' . i saw it but it didnt look like virtual work method.

yes i saw your post... thanks for replying.. can you name a common book on structural engineering so that i can download it. also, what other approach is there to virtual work. why the one i stated is "difficult". is it wrong ??

i started studying calculus in a non rigorous way. in physics the non rigorous calculus works perfectly well. then i started reading rigorous calculus( from apostol) and since then any non rigorous analsis always leaves me thinking whether the statement is true in strict mathematical sense. for...

can you please state the the principal of virtual work without using infinitesimals.. (i don't know how to type mathematical symbols here... like how to type greek symbols and partial derivative symbols. how do i do that?)

rigorous statement of virtual work principle?? in the texts on mechanics the virtual work principle is always stated in 'infitesimal form'. is there a "proper" way to write the principle of virtual work in which we don't leave it in terms of INFINITESIMALS.

bernoulli's eqn does not state that wherever the velocity of fluid increases,the pressure of the fluid decreases. there is a gravity head too... so even if velocity increases in some direction then the pressure gradient may still be positive in that direction.