F\: = \frac{\mathrm{dp} }{\mathrm{d} t} = \frac{\mathrm{d} }{\mathrm{d} t}\left ( \frac{m_{0}\cdot v}{\sqrt{1-\frac{v^{2}}{c^{2}}}} \right ) = m_{0}\cdot\frac{\mathrm{d} }{\mathrm{d} t}\left ( \frac{v}{\sqrt{1-\frac{v^{2}}{c^{2}}}} \right )