9478 / 2027

Chapter 1

Quantities and Measurement

State what a result means, give its unit where applicable, and justify its precision.

Convert units, assess measurement uncertainty and calculate with vector components.

Base and derived units, prefixes, homogeneity, estimates, errors, derived uncertainties, and coplanar vectors. For 9478 (2027).

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Choose a topic

  1. Units, dimensions and estimates

    Convert prefixes, derive units, check equations and justify the approximate size of a quantity.

  2. Errors, accuracy and precision

    Distinguish scatter from systematic effects and choose an improvement that addresses the actual limitation.

  3. Uncertainty in calculated results

    Select absolute or fractional uncertainty rules, check numerical bounds and identify the largest contribution.

  4. Vectors and perpendicular components

    Add and subtract coplanar vectors, resolve components and interpret the direction of a velocity change.