Question

Help with 8? I really need some help guys!

Answer 1

It sounds like you're supposed to find the average velocity $\bar v$ over the total 3.8 seconds, which would be given by

$\bar v=\dfrac{\Delta x}{\Delta t}=\dfrac{x-x_0}{t-t_0}$

where $x$ is the displacement at time $t$, $x_0=0$ is the initial displacement from the origin, and $t_0=0$ is the starting time. Then the average velocity over the total 3.8 seconds,

$\bar v=\dfrac xt,$

is determined entirely by the displacement of the particle after 3.8 seconds, so that

$\bar v=\dfrac{-9.23\,\mathrm m}{3.8\,\mathrm s}\approx-2.4\,\dfrac{\mathrm m}{\mathrm s}$