Physics (AS & A Level) · May / June 2020 · Paper 12 · Question 9

A mass m₁ travelling with speed u₁ collides with a mass m₂ travelling with speed u₂ in the same direction. After the collision, mass m₁ has speed v₁ and mass m₂ has speed v₂ in the same direction. The collision is perfectly elastic. Which equation is not correct?

1. Am₁u₁² – m₁v₁² = m₂v₂² – m₂u₂²
2. Bv₂ + u₂ = v₁ + u₁
3. Cm₁(u₁ – v₁) = m₂(v₂ – u₂)
4. Dm₁(u₁ – v₁)² = m₂(u₂ – v₂)²

As printed in the paper