Edexcel M1 — Question 5 13 marks

Exam BoardEdexcel
ModuleM1 (Mechanics 1)
Marks13
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicConstant acceleration (SUVAT)
TypeTwo vehicles: overtaking or meeting (algebraic)
DifficultyModerate -0.3 This is a standard two-particle SUVAT problem requiring calculation of acceleration, sketching velocity-time graphs, and finding when vehicles meet by equating distances. While multi-part with several steps, it involves routine application of kinematic equations with no novel problem-solving insight required—slightly easier than average due to straightforward setup and clear methodology.
Spec3.02b Kinematic graphs: displacement-time and velocity-time3.02c Interpret kinematic graphs: gradient and area3.02d Constant acceleration: SUVAT formulae

5. A car and a motorbike are at rest adjacent to one another at a set of traffic lights on a long, straight stretch of road. They set off simultaneously at time \(t = 0\). The motorcyclist accelerates uniformly at \(6 \mathrm {~ms} ^ { - 2 }\) until he reaches a speed of \(30 \mathrm {~ms} ^ { - 1 }\) which he then maintains. The car driver accelerates uniformly for 9 seconds until she reaches \(36 \mathrm {~ms} ^ { - 1 }\) and then remains at this speed.
  1. Find the acceleration of the car.
  2. Draw on the same diagram speed-time graphs to illustrate the movements of both vehicles.
  3. Find the value of \(t\) when the car again draws level with the motorcyclist.

AnswerMarks Guidance
(a) \(\text{acc}^n = \frac{36-0}{9} = 4 \text{ ms}^{-2}\)M1 A1
(b) [Graph showing speed vs time with car and motorbike curves]B4
(c) after \(t\) seconds \(s_M = \frac{1}{2}(5)(30) + 30(t-5)\) (for \(t > 5\))M1 A1
after \(t\) seconds \(s_C = \frac{1}{2}(9)(36) + 36(t-9)\) (for \(t > 9\))M1 A1
car level with bike when \(s_M = s_C\) i.e. \(75 + 30t - 150 = 162 + 36t - 324\)M2
\(t = 14.5\) secondsA1 (13)
(a) $\text{acc}^n = \frac{36-0}{9} = 4 \text{ ms}^{-2}$ | M1 A1 |

(b) [Graph showing speed vs time with car and motorbike curves] | B4 |

(c) after $t$ seconds $s_M = \frac{1}{2}(5)(30) + 30(t-5)$ (for $t > 5$) | M1 A1 |

after $t$ seconds $s_C = \frac{1}{2}(9)(36) + 36(t-9)$ (for $t > 9$) | M1 A1 |
car level with bike when $s_M = s_C$ i.e. $75 + 30t - 150 = 162 + 36t - 324$ | M2 |
$t = 14.5$ seconds | A1 | (13) |
5. A car and a motorbike are at rest adjacent to one another at a set of traffic lights on a long, straight stretch of road. They set off simultaneously at time $t = 0$. The motorcyclist accelerates uniformly at $6 \mathrm {~ms} ^ { - 2 }$ until he reaches a speed of $30 \mathrm {~ms} ^ { - 1 }$ which he then maintains. The car driver accelerates uniformly for 9 seconds until she reaches $36 \mathrm {~ms} ^ { - 1 }$ and then remains at this speed.
\begin{enumerate}[label=(\alph*)]
\item Find the acceleration of the car.
\item Draw on the same diagram speed-time graphs to illustrate the movements of both vehicles.
\item Find the value of $t$ when the car again draws level with the motorcyclist.
\end{enumerate}

\hfill \mbox{\textit{Edexcel M1  Q5 [13]}}