Physics (AS & A Level) · May / June 2024 · Paper 11 · Question 12

Spheres X and Y form an isolated system. The mass of Y is greater than the mass of X. Sphere Y is initially stationary. Sphere X collides elastically with sphere Y. The speed of sphere X before the collision is u. Which statement must be correct?

1. ASphere X rebounds with a speed that is greater than u, and sphere Y moves off with a speed that is less than u.
2. BSphere X rebounds with a speed that is less than u, and sphere Y moves off with a speed that is also less than u.
3. CSphere X rebounds with speed u, and sphere Y remains stationary.
4. DSphere X remains stationary, and sphere Y moves off with a speed that is less than u.

As printed in the paper