Frequently in physics, one makes simplifying approximations. a common one in electricity is the notion of infinite charged sheets. this approximation is useful when a problem deals with points whose distance from a finite charged sheet is small compared to the size of the sheet. in this problem, you will look at the electric field from two finite sheets and compare it to the results for infinite sheets to get a better idea of when this approximation is valid. consider two thin disks, of negligible thickness, of radius r oriented perpendicular to the x axis such that the x axis runs through the center of each disk. (figure 1) the disk centered at x = 0 has positive charge density eta, and the disk centered at x = a has negative charge density -eta, where the charge density is charge per unit area. what is the magnitude e of the electric field at the point on the x axis with x coordinate a/2? express your answer in terms of eta, r, a., and the permittivity of free space element_0. e = 4 pi kn(1 - a/squareroot a^2 + r^2)

i need the answer to this too but idk it ; -;

c. magnitude and direction

russian is not my first language, so i'm afraid i can't write out an answer in russian, but hopefully you can find a way to do so. here's my best translation of the problem: you're given a plot of a particle's position in one-dimensional space over time, and you're asked to find either the total distance traveled by the particle after 6 seconds had elapsed, or the total displacement of the particle after 6 seconds.

if you want the total distance traveled, you would first need to determine the particle's velocity as a function of time, then integrate that over the 6-second interval. we know the position function is quadratic with roots at 0 and 6, so we have

where is unknown. because the position is parabolic, there is symmetry about the midpoint at , and we know that

so that the position function is

which means the velocity is

then the total distance traveled is

so the total distance traveled is 20 m.

on the other hand, if you want to find displacement: the particle starts at and ends at , so its displacement is 0.