| Exam Board | OCR MEI |
|---|---|
| Module | M1 (Mechanics 1) |
| Year | 2011 |
| Session | January |
| Marks | 6 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Vectors Introduction & 2D |
| Type | Resultant of three coplanar forces |
| Difficulty | Moderate -0.8 This is a straightforward M1 mechanics question requiring basic resolution of forces into components using trigonometry, then finding magnitude and direction of the resultant. It's routine application of standard techniques with no problem-solving insight needed, making it easier than average but not trivial since it requires careful trigonometric work. |
| Spec | 3.03e Resolve forces: two dimensions3.03p Resultant forces: using vectors |
2 Fig. 2 shows two forces acting at A. The figure also shows the perpendicular unit vectors $\mathbf { i }$ and $\mathbf { j }$ which are respectively horizontal and vertically upwards.
The resultant of the two forces is $\mathbf { F } \mathbf { N }$.
\begin{figure}[h]
\begin{center}
\includegraphics[alt={},max width=\textwidth]{e36ef805-beff-4125-b332-439ccb0d91c4-3_264_922_479_609}
\captionsetup{labelformat=empty}
\caption{Fig. 2}
\end{center}
\end{figure}
(i) Find $\mathbf { F }$ in terms of $\mathbf { i }$ and $\mathbf { j }$, giving your answer correct to three significant figures.\\
(ii) Calculate the magnitude of $\mathbf { F }$ and the angle that $\mathbf { F }$ makes with the upward vertical.
\hfill \mbox{\textit{OCR MEI M1 2011 Q2 [6]}}