Edexcel M1 2001 June — Question 3 9 marks

Exam BoardEdexcel
ModuleM1 (Mechanics 1)
Year2001
SessionJune
Marks9
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicConstant acceleration (SUVAT)
TypeRead and interpret velocity-time graph
DifficultyModerate -0.8 This is a straightforward M1 question requiring basic SUVAT calculations (distance from trapezium area under graph), recognition that constant gradient implies constant acceleration/force, and application of F=ma with given deceleration. All steps are routine with no problem-solving insight needed, making it easier than average.
Spec3.02b Kinematic graphs: displacement-time and velocity-time3.02c Interpret kinematic graphs: gradient and area3.02d Constant acceleration: SUVAT formulae3.03d Newton's second law: 2D vectors

3. \begin{figure}[h]
\captionsetup{labelformat=empty} \caption{Figure 2} \includegraphics[alt={},max width=\textwidth]{218383c1-0875-46f2-9416-8e827065a7a6-3_540_1223_348_455}
\end{figure} A car of mass 1200 kg moves along a straight horizontal road. In order to obey a speed restriction, the brakes of the car are applied for 3 s , reducing the car's speed from \(30 \mathrm {~m} \mathrm {~s} ^ { - 1 }\) to \(17 \mathrm {~m} \mathrm {~s} ^ { - 1 }\). The brakes are then released and the car continues at a constant speed of \(17 \mathrm {~m} \mathrm {~s} ^ { - 1 }\) for a further 4 s . Figure 2 shows a sketch of the speed-time graph of the car during the 7 s interval. The graph consists of two straight line segments.
  1. Find the total distance moved by the car during this 7 s interval.
  2. Explain briefly how the speed-time graph shows that, when the brakes are applied, the car experiences a constant retarding force.
  3. Find the magnitude of this retarding force.

Question 3:
Part (a):
AnswerMarks Guidance
\(\text{Distance} = \frac{1}{2}(30+17) \times 3 + 4 \times 17\)M1 A1 M1
\(= 138.5 \text{ m}\)A1 (4 marks)
OR: \(\frac{1}{2} \times 3(30-17) + 3 \times 17 + 4 \times 17 = 138.5 \text{ m}\)M1 A1 M1 A1
Part (b):
AnswerMarks Guidance
Straight line on \(v\)–\(t\) graph \(\Rightarrow\) constant decelerationM1
\(F = ma \Rightarrow F\) constantA1 cso (2 marks)
Part (c):
AnswerMarks Guidance
\(\text{Deceleration} = \frac{30-17}{3}\)M1
\(\text{Force} = 1200 \times \left(\frac{30-17}{3}\right) \approx 5200 \text{ N}\)M1 A1 (3 marks) Total: 9
## Question 3:

### Part (a):
$\text{Distance} = \frac{1}{2}(30+17) \times 3 + 4 \times 17$ | M1 A1 M1 |
$= 138.5 \text{ m}$ | A1 | (4 marks)

**OR:** $\frac{1}{2} \times 3(30-17) + 3 \times 17 + 4 \times 17 = 138.5 \text{ m}$ | M1 A1 M1 A1 |

### Part (b):
Straight line on $v$–$t$ graph $\Rightarrow$ constant deceleration | M1 |
$F = ma \Rightarrow F$ constant | A1 cso | (2 marks)

### Part (c):
$\text{Deceleration} = \frac{30-17}{3}$ | M1 |
$\text{Force} = 1200 \times \left(\frac{30-17}{3}\right) \approx 5200 \text{ N}$ | M1 A1 | (3 marks) **Total: 9**

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3.

\begin{figure}[h]
\begin{center}
\captionsetup{labelformat=empty}
\caption{Figure 2}
  \includegraphics[alt={},max width=\textwidth]{218383c1-0875-46f2-9416-8e827065a7a6-3_540_1223_348_455}
\end{center}
\end{figure}

A car of mass 1200 kg moves along a straight horizontal road. In order to obey a speed restriction, the brakes of the car are applied for 3 s , reducing the car's speed from $30 \mathrm {~m} \mathrm {~s} ^ { - 1 }$ to $17 \mathrm {~m} \mathrm {~s} ^ { - 1 }$. The brakes are then released and the car continues at a constant speed of $17 \mathrm {~m} \mathrm {~s} ^ { - 1 }$ for a further 4 s . Figure 2 shows a sketch of the speed-time graph of the car during the 7 s interval. The graph consists of two straight line segments.
\begin{enumerate}[label=(\alph*)]
\item Find the total distance moved by the car during this 7 s interval.
\item Explain briefly how the speed-time graph shows that, when the brakes are applied, the car experiences a constant retarding force.
\item Find the magnitude of this retarding force.
\end{enumerate}

\hfill \mbox{\textit{Edexcel M1 2001 Q3 [9]}}