Physics (AS & A Level) · Oct / Nov 2022 · Paper 12 · Question 11

Two solid spheres form an isolated system. Sphere X moves with speed 6 cm s⁻¹ in a straight line directly towards a stationary sphere Y, as shown. The spheres have a perfectly elastic collision. After the collision, sphere X moves with speed 2 cm s⁻¹ in the same direction as before the collision. What is the speed of sphere Y?

1. A2 cm s⁻¹
2. B4 cm s⁻¹
3. C6 cm s⁻¹
4. D8 cm s⁻¹

As printed in the paper