| Exam Board | OCR MEI |
|---|---|
| Module | Paper 1 (Paper 1) |
| Year | 2018 |
| Session | June |
| Marks | 3 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Moments |
| Type | Resultant force on lamina |
| Difficulty | Moderate -0.3 This is a straightforward two-part statics problem requiring only horizontal force equilibrium and taking moments about one point. The setup is clear, forces are parallel, and students simply need to apply ΣF=0 and Στ=0 with basic arithmetic—slightly easier than a typical A-level mechanics question due to its directness and lack of complications. |
| Spec | 3.04a Calculate moments: about a point3.04b Equilibrium: zero resultant moment and force |
| Answer | Marks | Guidance |
|---|---|---|
| Answer | Marks | Guidance |
| \(F = 30+50 = 80 \text{ N}\) | B1 [1] | cao |
| Answer | Marks | Guidance |
|---|---|---|
| Answer | Marks | Guidance |
| Taking moments about the top of the rod: \(Fx = 50\times2\) | M1 | Or any other suitable point; all necessary terms must be present; each term must be a product of a force and a length |
| \(x = 1.25 \text{ m}\) | A1 [2] | cao |
## Question 7(i):
| Answer | Marks | Guidance |
|--------|-------|----------|
| $F = 30+50 = 80 \text{ N}$ | B1 [1] | cao |
## Question 7(ii):
| Answer | Marks | Guidance |
|--------|-------|----------|
| Taking moments about the top of the rod: $Fx = 50\times2$ | M1 | Or any other suitable point; all necessary terms must be present; each term must be a product of a force and a length |
| $x = 1.25 \text{ m}$ | A1 [2] | cao |
---7 A rod of length 2 m hangs vertically in equilibrium. Parallel horizontal forces of 30 N and 50 N are applied to the top and bottom and the rod is held in place by a horizontal force $F \mathrm {~N}$ applied $x \mathrm {~m}$ below the top of the rod as shown in Fig. 7.
\begin{figure}[h]
\begin{center}
\includegraphics[alt={},max width=\textwidth]{904025c9-6d68-4344-bd41-8c0fccfcf92f-05_445_390_609_824}
\captionsetup{labelformat=empty}
\caption{Fig. 7}
\end{center}
\end{figure}
(i) Find the value of $F$.\\
(ii) Find the value of $x$.
\hfill \mbox{\textit{OCR MEI Paper 1 2018 Q7 [3]}}