Physics (AS & A Level) · Feb / March 2016 · Paper 12 · Question 10

A particle of mass $m$, travelling with speed $u$, collides with a stationary particle of mass $M$. The velocities of the two particles before and after the collision are shown. Which vector diagram correctly shows the momenta before and after the collision?

1. AVector diagram with $mu$ horizontal, $\frac{mu}{2}$ at angle $\alpha$ to the horizontal, and $\frac{Mu}{3}$ at angle $\beta$ to the horizontal.
2. BVector diagram with $mu$ horizontal, $\frac{mu}{2}$ at angle $\beta$ to the horizontal, and $\frac{Mu}{3}$ at angle $\alpha$ to the horizontal.
3. CVector diagram with $mu$ horizontal, $\frac{mu}{2}$ at angle $\alpha$ to the horizontal, and $\frac{Mu}{3}$ at angle $\beta$ to the horizontal.
4. DVector diagram with $mu$ horizontal, $\frac{mu}{2}$ at angle $\beta$ to the horizontal, and $\frac{Mu}{3}$ at angle $\alpha$ to the horizontal.

As printed in the paper