| Exam Board | OCR MEI |
|---|---|
| Module | M1 (Mechanics 1) |
| Year | 2013 |
| Session | June |
| Marks | 3 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Newton's laws and connected particles |
| Type | Lift with passenger or load |
| Difficulty | Easy -1.2 This is a straightforward force diagram question requiring only identification of three forces (weight downward, normal reaction from below upward, normal reaction from above downward) on a block in equilibrium. It tests basic understanding of Newton's laws with no calculation or problem-solving required, making it easier than average. |
| Spec | 3.03a Force: vector nature and diagrams3.03b Newton's first law: equilibrium3.03f Weight: W=mg |
| Answer | Marks | Guidance |
|---|---|---|
| Answer | Marks | Guidance |
| Weight \(7g = 68.6\) N acting downwards | B1 | Must have correct direction |
| Normal reaction from 5 kg block on top: \((4+7)g = 110\) N... wait — Normal reaction from 5kg block = \((4+5)g\)... Normal force down from 5 kg block = \(4g = 39.2\) N downward | B1 | Force from block above = weight of 4 kg block |
| Normal reaction from 10 kg block upward = \((4+5+7)g = 156.8\) N upward | B1 | All three forces correctly labelled with directions |
# Question 1:
| Answer | Marks | Guidance |
|--------|-------|----------|
| Weight $7g = 68.6$ N acting downwards | B1 | Must have correct direction |
| Normal reaction from 5 kg block on top: $(4+7)g = 110$ N... wait — Normal reaction from 5kg block = $(4+5)g$... Normal force down from 5 kg block = $4g = 39.2$ N downward | B1 | Force from block above = weight of 4 kg block |
| Normal reaction from 10 kg block upward = $(4+5+7)g = 156.8$ N upward | B1 | All three forces correctly labelled with directions |
---1 Fig. 1 shows a pile of four uniform blocks in equilibrium on a horizontal table. Their masses, as shown, are $4 \mathrm {~kg} , 5 \mathrm {~kg} , 7 \mathrm {~kg}$ and 10 kg .
\begin{figure}[h]
\begin{center}
\includegraphics[alt={},max width=\textwidth]{83e69140-4abf-4713-85da-922ce7530e47-2_400_568_434_751}
\captionsetup{labelformat=empty}
\caption{Fig. 1}
\end{center}
\end{figure}
Mark on the diagram the magnitude and direction of each of the forces acting on the 7 kg block.
\hfill \mbox{\textit{OCR MEI M1 2013 Q1 [3]}}