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
![x(t)=ax(x-6)](/tex.php?f=x(t)=ax(x-6))
where
is unknown. because the position is parabolic, there is symmetry about the midpoint at
, and we know that
![x(3)=10\implies -9a=10\implies a=-\dfrac{10}9](/tex.php?f=x(3)=10\implies -9a=10\implies a=-\dfrac{10}9)
so that the position function is
![x(t)=-\dfrac{10}9x(x-6)](/tex.php?f=x(t)=-\dfrac{10}9x(x-6))
which means the velocity is
![v(t)=\dfrac{\mathrm dx}{\mathrm dt}=-\dfrac{20}9x+\dfrac{60}9](/tex.php?f=v(t)=\dfrac{\mathrm dx}{\mathrm dt}=-\dfrac{20}9x+\dfrac{60}9)
then the total distance traveled is
![\displaystyle\int_{t=0}^{t=6}|v(t)|\,\mathrm dt=\left\{\int_{t-0}^{t=3}-\int_{t=3}^{t=6}\right\}v(t)\,\mathrm dt=20](/tex.php?f=\displaystyle\int_{t=0}^{t=6}|v(t)|\,\mathrm dt=\left\{\int_{t-0}^{t=3}-\int_{t=3}^{t=6}\right\}v(t)\,\mathrm dt=20)
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.
![Решите , пожалуйста, номер 119 срочно](/tpl/images/02/00/M9QE2L40jE2VeavY.jpg)