A-LevelPhysicsDynamicsOct/Nov 2023Paper 1 Q71 Mark
Two blocks, of mass 0.20 kg and 0.50 kg, are connected by a light inextensible string that passes over a frictionless pulley. [Figure 7.1] The blocks are initially held stationary. The block of mass 0.20 kg rests on a rough horizontal surface. The block of mass 0.50 kg is suspended in air. Air resistance is negligible. When the blocks are released, they have an acceleration of magnitude 2.0 m s⁻². What is the magnitude of the frictional force between the block of mass 0.20 kg and the rough surface?
A3.5 N
B3.9 N
C4.5 N
D6.3 N
✓ Correct Answer
The correct answer is A: 3.5 N
📋 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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