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

Kinematics of motion in a straight line — practice question

A particle $P$ leaves point $O$ and then moves along a straight line. At time $t\,\text{s}$ after leaving $O$, the velocity of $P$ is $k(60t^2 - t^3)\,\text{m s}^{-1}$, where $k$ is a constant. The maximum velocity of $P$ is $6.4\,\text{m s}^{-1}$.
(i)[3]

Show that the constant is $k = 0.0002$.

(ii)[5]

At a point $A$ on the line, $P$ comes to instantaneous rest. Determine $OA$.

(iii)[2]

Find the magnitude of the acceleration of $P$ at point $A$.

(iv)[2]

Find the speed of $P$ when it next passes through $O$.

Worked solution & mark scheme

This 12-mark question has a full step-by-step worked solution and mark scheme. One marking point: From $\frac{dv}{dt} = k(120t - 3t^2)$

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