KE = \frac{1}{2}mv^{2}

1 Joule = 1 \frac{kg m^{2}}{s^{2}}

\begin{aligned}v_{1} & = (\frac{m_{1} − m_{2}}{m_{1} + m_{2}} ) v \\ v_{2} & = (\frac{2m_{1}}{m_{1} + m_{2}} ) v \end{aligned}

STI = \sqrt{(cΔt)^{2} − (Δx)^{2}}