A-LevelPhysicsNuclear physicsFeb/Mar 2025Paper 1 Q381 Mark

A stationary nucleus has nucleon number A. The nucleus decays by emitting a proton with speed v to form a new nucleus with speed u. The new nucleus and the proton move away from one another in opposite directions. Which equation gives v in terms of A and u?

Q: What is the correct answer to this A-Level Physics question?

The correct answer is B: v = (A - 1)u.

Q: What topic does this question test?

This question tests Nuclear physics in A-Level Physics (syllabus code 9702). It is worth 1 mark.

Av = ((A-1)/4)u

Bv = (A - 1)u

Cv = Au

Dv = (A + 1)u

✓ Correct Answer

The correct answer is B: v = (A - 1)u

📋 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.

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About This A-Level Physics Question

Topic

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

Source

This question appeared in the Cambridge A-Level Physics Feb/Mar 2025 examination, Paper 1 Variant 2.

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