• # question_answer A mass m moves with a velocity v and collides in elastically with another identical mass. After v collision the 1 st mass moves with velocity $\frac{v}{\sqrt{3}}$ in a direction perpendicular to the initial direction of motion. Find the speed of the second mass after collision. A)  v                                 B)  $\sqrt{3v}$ C)  $\frac{2}{\sqrt{3}}v$                           D)  $\frac{v}{\sqrt{3}}$

In x-direction $m{{u}_{1}}+0=0+m{{v}_{x}}$Or $mv=m{{v}_{x}}$${{v}_{x}}=v$ In y-direction $0+0\,=m\left( \frac{v}{\sqrt{3}} \right)\,-m{{v}_{y}},\,\,or\,\,{{v}_{y}}=\frac{v}{\sqrt{3}}$ Velocity of second mass after collision, $v'=\,\sqrt{{{\left( \frac{v}{\sqrt{3}} \right)}^{2}}+{{v}^{2}}}\,=\sqrt{\frac{4}{3}{{v}^{2}}}$$v'\,=\frac{2}{\sqrt{3}}v$