| Exam Board | OCR |
|---|---|
| Module | FM1 AS (Further Mechanics 1 AS) |
| Year | 2021 |
| Session | June |
| Marks | 7 |
| Topic | Momentum and Collisions |
| Type | String becomes taut problem |
| Difficulty | Standard +0.3 This is a standard Further Mechanics 1 string-becomes-taut problem requiring conservation of momentum, impulse calculation, and energy loss. While it involves multiple parts and FM1 content (making it harder than basic mechanics), it follows a completely standard template with straightforward application of formulas: find common velocity using momentum conservation, calculate impulse from change in momentum, and find KE loss by comparing initial and final energies. No novel insight or complex problem-solving required—just methodical application of well-practiced techniques. |
| Spec | 6.03f Impulse-momentum: relation |
1 A particle $A$ of mass 3.6 kg is attached by a light inextensible string to a particle $B$ of mass 2.4 kg .\\
$A$ and $B$ are initially at rest, with the string slack, on a smooth horizontal surface. $A$ is projected directly away from $B$ with a speed of $7.2 \mathrm {~ms} ^ { - 1 }$.
\begin{enumerate}[label=(\alph*)]
\item Calculate the speed of $A$ after the string becomes taut.
\item Find the impulse exerted on $A$ at the instant that the string becomes taut.
\item Find the loss in kinetic energy as a result of the string becoming taut.
\end{enumerate}
\hfill \mbox{\textit{OCR FM1 AS 2021 Q1 [7]}}