A-level · Kinematics

Motion in two dimensions with vectorsExam-style questions

Why the a → v → r calculus chain works component-by-component in 2D, that speed is the magnitude of the velocity vector, and how "parallel to" and "perpendicular to" a direction become simple component conditions.

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

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1
Two pucks, $A$ and $B$ , slide across a smooth horizontal air-hockey table. Both pucks may be modelled as particles, and each moves in a straight line.

$A$ slides with constant velocity $(-1.5\mathbf{i} + 2\mathbf{j})\ \text{m s}^{-1}$

$B$ is struck at the point with position vector $(0.4\mathbf{i} - 0.3\mathbf{j})$ metres. It then slides in a straight line and passes over the point with position vector $(-0.5\mathbf{i} + 0.9\mathbf{j})$ metres.

Show that the direction of motion of $B$ is parallel to the direction of motion of $A$ .

(3 marks)
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