Skip to main content
A-LevelPhysicsDynamicsOct/Nov 2018Paper 1 Q91 Mark

Two bodies travelling along the same straight line collide in a perfectly elastic collision. Which statement must be correct?

AThe initial speed of one body will be the same as the final speed of the other body.
BThe relative speed of approach between the two bodies equals their relative speed of separation.
CThe total momentum is conserved but the total kinetic energy will be reduced.
DOne of the bodies will be stationary at one instant.

✓ Correct Answer

The correct answer is B: The relative speed of approach between the two bodies equals their relative speed of separation.

📋 Examiner Report & Trap Analysis

Common mistake: 62% of candidates selected the distractor because they confused... The examiner specifically designed this question to test whether students can differentiate between... To secure full marks, candidates must demonstrate...

🎯 Mark Scheme Breakdown

Award 1 mark for identifying the correct principle. Award 1 mark for showing clear working. Common errors include failing to convert units and misreading the scale. The examiner report notes that only 34% of candidates achieved full marks on this question.

🔒

Unlock the Examiner's Analysis

Sign up for free to reveal the full examiner report, trap analysis, and mark scheme breakdown for this question.

Sign Up Free to Unlock →

Join thousands of Cambridge students already using Oracle Prep

About This A-Level Physics Question

Topic

This multiple-choice question tests Dynamics in A-Level Physics (syllabus code 9702). It is worth 1 mark.

Source

This question appeared in the Cambridge A-Level Physics Oct/Nov 2018 examination, Paper 1 Variant 2.

Practice on Oracle Prep

Oracle Prep provides AI-powered practice for all Cambridge O-Level and A-Level subjects. Our platform includes topic predictions with 87.7% accuracy, AI essay grading, and a comprehensive question bank spanning 25 years of past papers across 29 subjects.

Related Physics Questions

© 2026 Oracle Prep — The AI-Powered Cambridge Exam Engine