Salam Academy
Paper 3 · Module

Kinematics

5 subtopics≈ 170 min in total
  1. Constant acceleration (suvat)

    Five quantities, five formulae. Choose a positive direction, list what you know, and pick the formula that leaves out the one quantity you neither know nor need.

    ≈ 35 min
  2. Motion graphs

    A velocity–time graph tells the whole story of a journey: its gradient is the acceleration and the area under it is the displacement. Most graph questions are really area questions in disguise.

    ≈ 30 min
  3. Vertical motion under gravity

    Everything falls with the same acceleration, g=10 m s−2g=10\ \text{m s}^{-2} downwards. Choose up as positive, set a=−10a=-10, and suvat does the rest, including the moment the ball hangs still at the top.

    ≈ 35 min
  4. Variable acceleration

    When acceleration changes with time, suvat is off the table. Differentiate to go from displacement to velocity to acceleration; integrate, with a constant each time, to come back.

    ≈ 35 min
  5. Position, velocity and acceleration vectors

    An object starting at r0\mathbf r_0 and moving with constant velocity v\mathbf v is at r=r0+vt\mathbf r=\mathbf r_0+\mathbf vt after time tt. Speed is the magnitude of velocity. "Due north" means the i\mathbf i-component is zero; two objects meet when their position vectors are equal at the same time.

    ≈ 35 min