A student is revising for a physics examination and writes down the following statements about physical quantities and their units. For each statement, state whether it is correct or incorrect, and if incorrect, give the correct unit. Statement 1: 'The SI unit of momentum is kg/s.' Statement 2: 'The SI unit of the moment of a force is Newton metre (Nm).' Statement 3: 'The SI unit of gravitational field strength is N/kg.' Statement 4: 'The SI unit of velocity is m/s².'
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
A student is revising for a physics examination and writes down the following statements about physical quantities and their units. Statement 1: 'The SI unit of momentum is kg/s.' Statement 2: 'The SI unit of the moment of a force is Newton metre (Nm).' Statement 3: 'The SI unit of gravitational field strength is N/kg.' Statement 4: 'The SI unit of velocity is m/s².'
Model answer (4 marks)
Statement 1: Incorrect – the SI unit of momentum is kilogram metres per second (kg m/s).
Statement 2: Correct – the SI unit of the moment of a force is Newton metre (Nm).
Statement 3: Correct – the SI unit of gravitational field strength is Newton per kilogram (N/kg).
Statement 4: Incorrect – the SI unit of velocity is metres per second (m/s).
Statement 2: Correct – the SI unit of the moment of a force is Newton metre (Nm).
Statement 3: Correct – the SI unit of gravitational field strength is Newton per kilogram (N/kg).
Statement 4: Incorrect – the SI unit of velocity is metres per second (m/s).
Examiner tips
- Use the exact wording from the mark scheme – e.g. ‘Incorrect – the SI unit is …’. Show the unit in the correct form (kg m/s, Nm, N/kg, m/s).
- Remember to include the unit symbols with the correct spacing and no extra words.
Mark scheme (4 marks)
- Statement 1 is incorrect; the correct unit of momentum is kilogram metres per second (kg m/s).
- Statement 2 is correct; the SI unit of the moment of a force is Newton metre (Nm).
- Statement 3 is correct; the SI unit of gravitational field strength is N/kg.
- Statement 4 is incorrect; the correct unit of velocity is metres per second (m/s).
Key terms in this question
momentum · moment of a force · gravitational field strength · velocity
Related
- All Pearson Edexcel International GCSE Physics (4PH1) revision notes →
- How to answer a "State" question →
- Decode the mark scheme abbreviations →
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