Mathematics 9709 · AS & A Level · Kinematics of motion in a straight line

Kinematics of motion in a straight line — practice question

A particle $P$ is launched vertically upwards from a point on the ground at a speed of $17\,\text{m s}^{-1}$. A second particle $Q$ is launched vertically upwards from the same point at a speed of $7\,\text{m s}^{-1}$. Particle $Q$ is launched $T$ seconds after particle $P$.
(i)[2]

Since the particles reach the ground simultaneously, determine the value of $T$.

(ii)[6]

At a particular instant when both $P$ and $Q$ are moving, $P$ is $5\,\text{m}$ above $Q$. Determine the magnitude of the velocity of each particle at this instant.

Worked solution & mark scheme

This 8-mark question has a full step-by-step worked solution and mark scheme. One marking point: Apply time-to-maximum-height reasoning to P and Q

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