Mathematics 9709 · AS & A Level · Representation of data

Representation of data — practice question

$O$, $A$ and $B$ are three points lying on one straight line on a smooth horizontal surface. A particle $P$ of mass $0.6\,\text{kg}$ travels along the line. At time $t\,\text{s}$, the particle’s displacement from $O$ is $x\,\text{m}$ and its speed is $v\,\text{m s}^{-1}$. The only horizontal force on $P$ has magnitude $0.4v^{\frac{1}{2}}\,\text{N}$ and acts in the direction $OA$. At the start, the particle is at $A$, where $x = 1$ and $v = 1$.
(i)[2]

Show that $3v^{\frac{1}{2}}\,\frac{dv}{dx} = 2$.

(ii)[4]

Express $v$ in terms of $x$.

(iii)[3]

Given that $AB = 7\,\text{m}$, determine the value of $t$ when $P$ passes through $B$.

Worked solution & mark scheme

This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: Applies Newton’s second law $a=v\dfrac{dv}{dx}$

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