Scalars and vectors
Cambridge A-Level Physics (9702) · Unit 1: Physical quantities and units · 7 flashcards
Scalars and vectors is topic 1.4 in the Cambridge A-Level Physics (9702) syllabus , positioned in Unit 1 — Physical quantities and units , alongside Physical quantities, SI units and Errors and uncertainties. In one line: A scalar quantity is one that has magnitude only, not direction. Examples include: mass, temperature, time, distance, speed, energy, and work.
Marked as AS Level: examined at AS Level in Paper 1 (Multiple Choice), Paper 2 (AS Structured Questions) and Paper 3 (Advanced Practical Skills). The same content may also be assumed in Paper 4 (A Level Structured Questions).
The deck below contains 7 flashcards — 3 definitions, 2 key concepts and 2 calculations — covering the precise wording mark schemes reward. Use the 3 definition cards to lock down command-word answers (define, state), then move on to the concept and calculation cards to handle explain, describe, calculate and compare questions.
A scalar quantity and provide two examples from physics
A scalar quantity is one that has magnitude only, not direction. Examples include: mass, temperature, time, distance, speed, energy, and work.
What the Cambridge 9702 syllabus says
Official 2025-2027 spec · AS LevelThese are the exact learning outcomes Cambridge sets for this topic. The candidate is expected to be able to do each of these on the relevant paper.
- understand the difference between scalar and vector quantities and give examples of scalar and vector quantities included in the syllabus
- add and subtract coplanar vectors
- represent a vector as two perpendicular components
- www.cambridgeinternational.org/alevel
Cambridge syllabus keywords to use in your answers
These are the official Cambridge 9702 terms tagged to this section. Mark schemes credit responses that use the exact term — weave them into your answers verbatim rather than paraphrasing.
Tips to avoid common mistakes in Scalars and vectors
- › Express every unit in the term (e.g., N = kg m s⁻²) then combine them; moment of force SI base units are kg m² s⁻².
- › Distinguish between physical quantities and their units; ensure your answer includes both a magnitude and a unit for physical quantities.
- › Always refer back to the seven SI base units defined in the syllabus; ensure mass is converted to kg for base unit consistency.
- › Ensure you distinguish between a quantity (like spring constant) and its units (like N m⁻¹); remember all physical quantities have a magnitude and a unit.
- › Check that the units used in a calculation are consistent, particularly for prefixes like k, μ, or M, before finalizing your answer.
Define a scalar quantity and provide two examples from physics.
A scalar quantity is one that has magnitude only, not direction. Examples include: mass, temperature, time, distance, speed, energy, and work.
Define a vector quantity and provide two examples from physics.
A vector quantity is one that has both magnitude and direction. Examples include: displacement, velocity, acceleration, force, momentum, and weight.
Describe the process of adding two coplanar vectors graphically.
Coplanar vectors can be added using a vector triangle or parallelogram. Draw the vectors to scale, head-to-tail (triangle) or from a common origin (parallelogram), then measure the resultant vector's magnitude and direction.
Explain how to resolve a vector into two perpendicular components.
A vector can be resolved into horizontal (x) and vertical (y) components using trigonometry. If the vector has magnitude 'A' and makes an angle 'θ' with the horizontal, then Ax = Acosθ and Ay = Asinθ.
Two forces, 3N and 4N, act on an object at right angles to each other. What is the magnitude of the resultant force?
Use Pythagorean theorem: Resultant force = √(3² + 4²) = √25 = 5N.
Describe the difference between distance and displacement.
Distance is a scalar quantity representing the total length of the path traveled. Displacement is a vector quantity representing the change in position from start to finish, with a specific direction.
A car travels 50m North, then 30m East. What is the magnitude of the car's displacement?
The displacement is the hypotenuse of a right-angled triangle. Displacement = √(50² + 30²) = √(2500+900) = √3400 ≈ 58.3m
Review the material
Read full revision notes on Scalars and vectors — definitions, equations, common mistakes, and exam tips.
Read NotesMore topics in Unit 1 — Physical quantities and units
Scalars and vectors sits alongside these A-Level Physics decks in the same syllabus unit. Each uses the same spaced-repetition system, so progress in one informs the next.
Key terms covered in this Scalars and vectors deck
Every term below is defined in the flashcards above. Use the list as a quick recall test before your exam — if you can't define one of these in your own words, flip back to that card.
How to study this Scalars and vectors deck
Start in Study Mode, attempt each card before flipping, then rate Hard, Okay or Easy. Cards you rate Hard come back within a day; cards you rate Easy push out to weeks. Your progress is saved in your browser, so come back daily for 5–10 minute reviews until every card reads Mastered.
Study Mode
Rate each card Hard, Okay, or Easy after flipping.