A particle of mass m is moving along the x - axis with speed v when it collides with a particle of mass 2m initially at rest. After the collisions, the first particle has come to rest, and the second particle has split into two equal - mass pieces that move at equal angles θ > 0 with the x - axis, as shown in the figure. Which of the following statements correctly describes the speeds of the two pieces?

Know your College Admission Chances Based on your Rank/Percentile, Category and Home State.
Get your JEE Main Personalised Report with Top Predicted Colleges in JoSA
mv = mv' cos θ + mv' cos θ
.