Cambridge IGCSE Physics Notes 1.1: Physical Quantities and Measurement
Cambridge IGCSE Physics 0625 and 0972 notes on measurement techniques, repeated readings, scalars, vectors, and vector resultants.
Q: What does Cambridge IGCSE Physics Notes 1.1: Physical Quantities and Measurement cover?
A: It follows official Cambridge Physics section 1.1 for syllabuses 0625 and 0972, with Core ideas separated from Supplement depth.
Measurement turns a physical idea into a value with a unit, while scalar and vector classification determines how quantities can be combined.
The ideas that organise this section
- Choose an instrument whose range and scale suit the quantity.
- Measure repeated small intervals or distances together, then divide to reduce percentage uncertainty.
- Scalars have magnitude; vectors have magnitude and direction.
Core route
Core candidates should be ready to describe, calculate, interpret, and apply the following:
- Use rulers, measuring cylinders, clocks, and digital timers appropriately.
- Find an average value by measuring multiples, such as several pendulum oscillations.
Supplement route
Extended candidates study all Core content and add the following depth:
- Classify the syllabus quantities as scalars or vectors.
- Determine the resultant of two perpendicular forces or velocities graphically or by calculation.
Formula route
- Relationship: resultant squared = first component squared + second component squared.
Write the relationship before substituting. Convert units first, keep extra figures during working, and round only the final answer to sensible precision.
Build a connected model
In Physical Quantities and Measurement, a strong answer connects the named quantity or model to observable evidence. Begin by defining the physical quantity in words or with its relationship. Identify which values are scalars and which require a direction. Represent the situation with a labelled diagram, graph, field pattern, ray or circuit when that makes the relationship visible. The representation is part of the reasoning: its labels, arrows and scale should agree with the written explanation.
For a calculation, write the governing relationship before substitution, convert prefixes and time units, keep unrounded values during working and attach the correct final unit. For a qualitative question, use a cause-link-consequence chain. Name what changes, state the physical mechanism that links the change to the system, and then give the measurable result. If two cases are compared, hold unrelated variables constant and use the same physical principle for both.
