a. List variables
[tex]\begin{gathered} m_{1i}=\text{ 0.015 kg} \\ v_{1i}=\text{ 0.225 m/s} \\ m_{2i}=\text{ 0.03 kg} \\ v_{2i}\text{ =-0.18 m/s} \\ m_{1f}=\text{ 0.015 kg} \\ v_{1f}=-0.315\text{ kg} \\ m_{2f}=\text{ 0.03 kg} \\ v_{2f}\text{ = ?} \end{gathered}[/tex]
b. plug into the equation
[tex]\begin{gathered} m_{1i}v_{1i}+m_{2i}v_{2i}=m_{1f}v_{1f}+m_{2f}v_{2f} \\ 0.015\times0.225+0.03\text{ }\times(-0.18)=0.015\times(-0.315)+0.03(v_{2f}) \end{gathered}[/tex]
c. solve for missing
[tex]\begin{gathered} v_{2f}=\frac{0.015\times0.225+0.03(-0.18)-0.015\times(-0.315)}{0.03} \\ =0.09\text{ m/s} \end{gathered}[/tex]
