Recent content by stefano77

unit of measurement '' rad '' appears and disappears as in calculating angular frequency as square root of k/m in spring-mass model.how can l explain to students?not as a dogma? you can say unit of measuremnt is the inverse of second, but what about the final formula of rad/ s ? rad appears in...

it is just not parallel to the plates. But there is symmetry so that charge is uniformly distributed. l suppose.

I only change dielectric to conducting in this problem https://www.physicsforums.com/threads/oblique-slab-dieletric-material-in-a-capacitor.1015785/#post-6639355

I use this observation https://www.physicsforums.com/threads/oblique-slab-dieletric-material-in-a-capacitor.1015785/post-6639355

charges will be distributed on the the slab in an uniform way cause of the simmetry. The problem is similar to capacitor with parallel plates with electric field null outside the slab. Then the original electric field don't change. But this is the problem in my opionion. The electric field...

sorry for my bad english, l am italian. l would like to know what is the value of E inside the capacitor. the slab is finite, but l suppose infinite as it happens in these exercises. Moreover I suppose slab far from plates of capacitor

l have an oblique slab of material conducting in a capacitor. The plates of capacitor are infinite, parallel and far. How is E field inside capacitor?

how can l prove Newton's law is time invariant? if x (t) is a solution of dd/ddx x(t) = f(x(t)) then if l put y(-t) dd/ddt y(t)=dd/ddt x(-t). Now how dd/ddt x(-t) is equal to f(x(-t))?dd/ddt is second derivative with respect to time

thank you so much for your observation...you have solved the problem...here's the solution... then, ##\rho_{inside}## is null because the dieletric is homogenous and ##\sigma## is costant on all dielectric for symmetry so that we can consider the dieletric equivalent to an oblique capacitor with...

why with a uniform dieletric spere field changes and with slab no?

in the text there is an angle with the horizontal ( 30 degrees), but that could be useful with boundary conditions. In the text there is the following note, too: the plates are very far and with infinite area. Moreover the slab is 5 cm thick, but l don't understand how to calculate E in vacuum...

that's the point. there are not symmetric condition anymore in this case.Then you can't suppose the direction of E vector a priori.

first of all thank you everyone for your answers. it is very kind of you. then l know ## D_{1n} ## = ## D_{2n}## and ## E_{1t} ## = ## E_{2t}## , but you don't know how is the D and E value ( total) in vacuum.(they are modified by dielectric) you could apply Laplace equation, but lf l use...

the charge on the plates aren't modified, but ##E_{total}## =##E_{capacitor}##+##E_{dielectric}## is modified, so that you don't know the direction of ##E_{total}## to apply boundary conditions