A-level · Quantities & units

Modelling assumptions & SI unitsExam-style questions

What each standard modelling word actually lets you ignore — particle, light, inextensible, smooth, rigid, uniform — so you can read an assumption off a question and know its consequence, the SI units mechanics is built on, and how to answer "state a limitation" by naming what the model leaves out.

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6 questions · A-level level · mark scheme and worked solution on each · no sign-up to try

DifficultyAllLevel 2Level 3
  1. 1
    Two particles are connected by a light inextensible string passing over a pulley. Explain why the two particles have the same acceleration.
    Level 3 · 1 markTry it
  2. 2
    State the SI units used for
    (a) force,
    (b) mass and (c) acceleration.
    Level 3 · 3 marksTry it
  3. 3
    A ball is kicked and its flight is modelled. State two modelling assumptions commonly made, and the effect of each.
    Level 3 · 2 marksTry it