GCSE · Formulae & rearranging

Substituting into formulaeExam-style questions

Why substitution is "replace the letter, keep the structure", why negatives must go in with brackets, and why the order of operations still rules once the numbers are in.

15 questions · GCSE (Higher) level · mark scheme and worked solution on each · no sign-up to try

DifficultyAllLevel 1Level 2Level 3Level 4Level 5
  1. 1
    v2=u2+2asv^2 = u^2 + 2as

    (a) Work out the value of vv when u=3u = 3, a=4a = 4 and s=5s = 5, given that v>0v > 0. (2 marks)

    (b) Make ss the subject of the formula. (2 marks)
    Level 3 · 4 marksTry it
  2. 2
    This formula gives an estimate of the braking distance, dd metres, of a car travelling at vv km/h on a dry road.

    d=v2160d = \frac{v^2}{160}

    Car AA is travelling at 4040 km/h when its driver brakes.

    Car BB is travelling at 8080 km/h when its driver brakes.

    How much longer is the braking distance of car BB than the braking distance of car AA?

    (2 marks)
    Level 3 · 2 marksTry it
  3. 3
    v=u+atv = u + at

    (a) Work out the value of vv when u=−6u = -6, a=3a = 3 and t=4t = 4

    (b) P=3q2P = 3q^2

    Work out the value of PP when q=−5q = -5
    Level 3 · 3 marksTry it
  4. 4
    s=ut+12at2s = ut + \dfrac{1}{2}at^2

    Work out the value of ss when u=5u = 5, a=−2a = -2 and t=6t = 6
    Level 3 · 2 marksTry it
  5. 5
    E=12mv2E = \dfrac{1}{2}mv^2

    Work out the value of EE when m=8m = 8 and v=5v = 5.
    Level 3 · 2 marksTry it