A bike path starts on one side of the parking lot, goes around a small pond, and comes out on the other end of the parking lot. Following the path, a biker rides 100.0 meters directly east, then turns south and rides 200.0 meters. From there, she turns and rides 150.0 meters at an angle of 30.0° south of west. Turning one last time, she rides 250.0 meters at an angle of 60.0° north of west. What is her final displacement (distance and direction) from her starting point?

the electric field is a “force field” around a charged object that illustrates the direction the electric force would push an imaginary 

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.