<![if !vml]><img width=337 height=64 src="тмм.files/image004.gif" v:shapes="_x0000_i1026"><![endif]>
<o:p> </o:p>
$$ \frac{d^2\vec{r}}{dt^2} = q\vec{E} - \frac{1}{2}C_d\rho_aA\left|\vec{v}\right|\vec{v} $$