Two particles are moving toward one another. Both of the
particles have a strong positive charge. As they move toward
one another, how will the electric force between the two
particles change?
A. The electric force will remain repulsive
and decrease in strength.
O
O
B. The electric force will remain repulsive
and increase in strength.
C. The electric force will become attractive
and decrease in strength.
D. The electric force will become attractive
and increase in strength.
O

the force on the thing and the distance the force moves the thing

in physics zero. in muscle fatigue could be high

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.