Vectors

This is a vector [math]\displaystyle{ \vec{\bf u} }[/math].

The time derivative of a vector [math]\displaystyle{ \vec{\bf u} = u \vec{\bf e} }[/math]is:

[math]\displaystyle{ \frac{d \vec{\bf u}}{dt} = \dot{u} \vec{\bf e} + \vec{\bf\Omega} \times \vec{\bf u} }[/math]