\note {
    \h1{The Acceleration Vector \{\vec{v}} }
    \equation {
        \vec{a} =
        \lim_{t\to 0} \frac{\vec{v}(t + \Delta t)-\vec{v}}{\Delta t} =
        \frac
            {\mathrm{d}\vec{v}}
            {\mathrm{d}t}
    }
}