Five equal negative charges are uniformly spaced in a semicircular arc of radius ro with its center at the origin. The charges positions in
polar coordinates are given by (o. 6.), where the values of 0 are 0°,
45°, 90°. 135º. and 180°. At the position (x, y) = (ro, -ro) in the 4th
quadrant, which statement best describes the direction of the
resulting electric field?
The direction is that of a 3rd quadrant angle.
The direction is that of a 2nd quadrant angle.
The direction is that of a 1st quadrant angle.
The direction is that of a 4th quadrant angle.

The direction is that of a 3rd quadrant angle

Explanation:

when you have 2 45 angles it equals to 90 then with the 90 we multiply by 2 due to the 2 adjacent angles equating to 180 which swings it to the 3rd quadrant angle

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.