OCR MEI Paper 1 2020 November — Question 5 5 marks

Exam BoardOCR MEI
ModulePaper 1 (Paper 1)
Year2020
SessionNovember
Marks5
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicTravel graphs
TypeVelocity-time graph sketching
DifficultyEasy -1.3 This is a straightforward SUVAT question requiring only direct application of basic definitions. Part (a) involves sketching three horizontal line segments on a velocity-time graph from given information. Parts (b) and (c) require simple arithmetic: calculating areas under the graph for distance and using signs for displacement. No problem-solving, algebraic manipulation, or conceptual insight needed—purely routine mechanics at an introductory level.
Spec3.02b Kinematic graphs: displacement-time and velocity-time3.02c Interpret kinematic graphs: gradient and area

5 A child is running up and down a path. A simplified model of the child's motion is as follows:
  • he first runs north for 5 s at \(4 \mathrm {~m} \mathrm {~s} ^ { - 1 }\);
  • he then suddenly stops and waits for 8 s ;
  • finally he runs in the opposite direction for 7 s at \(3.5 \mathrm {~m} \mathrm {~s} ^ { - 1 }\).
    1. Taking north to be the positive direction, sketch a velocity-time graph for this model of the child's motion.
Using this model,
  • calculate the total distance travelled by the child,
  • find his final displacement from his original position.

  • Question 5(a):
    AnswerMarks Guidance
    AnswerMarks Guidance
    Graph from 3 horizontal line segments with velocity \(4\) for \(0 \leq t \leq 5\), then \(-3.5\) for \(13 \leq t \leq 20\)B1 Graph from 3 horizontal line segments. Correct velocities labelled. Any lines joining the horizontal lines should be vertical
    Times \(t = 5, 13, 20\) or lengths of line segments \(5, 8, 7\) seenB1 [2]
    Question 5(b):
    AnswerMarks Guidance
    AnswerMarks Guidance
    Distance \(= (4 \times 5) + (7 \times 3.5)\) mM1 Finding the area of at least one region from their graph oe. May work directly from the information in the question without reference to their graph
    \(= 44.5\)A1 [2] cao
    Question 5(c):
    AnswerMarks Guidance
    AnswerMarks Guidance
    Displacement \(= 20 - 24.5 = -4.5\) mB1 [1] Allow for \(-4.5\) m or for \(4.5\) m south. Do not allow \(-4.5\) m south
    ## Question 5(a):
    
    | Answer | Marks | Guidance |
    |--------|-------|----------|
    | Graph from 3 horizontal line segments with velocity $4$ for $0 \leq t \leq 5$, then $-3.5$ for $13 \leq t \leq 20$ | B1 | Graph from 3 horizontal line segments. Correct velocities labelled. Any lines joining the horizontal lines should be vertical |
    | Times $t = 5, 13, 20$ or lengths of line segments $5, 8, 7$ seen | B1 [2] | |
    
    ---
    
    ## Question 5(b):
    
    | Answer | Marks | Guidance |
    |--------|-------|----------|
    | Distance $= (4 \times 5) + (7 \times 3.5)$ m | M1 | Finding the area of at least one region from their graph oe. May work directly from the information in the question without reference to their graph |
    | $= 44.5$ | A1 [2] | cao |
    
    ---
    
    ## Question 5(c):
    
    | Answer | Marks | Guidance |
    |--------|-------|----------|
    | Displacement $= 20 - 24.5 = -4.5$ m | B1 [1] | Allow for $-4.5$ m or for $4.5$ m south. Do not allow $-4.5$ m south |
    
    ---
    5 A child is running up and down a path. A simplified model of the child's motion is as follows:
    
    \begin{itemize}
      \item he first runs north for 5 s at $4 \mathrm {~m} \mathrm {~s} ^ { - 1 }$;
      \item he then suddenly stops and waits for 8 s ;
      \item finally he runs in the opposite direction for 7 s at $3.5 \mathrm {~m} \mathrm {~s} ^ { - 1 }$.
    \begin{enumerate}[label=(\alph*)]
    \item Taking north to be the positive direction, sketch a velocity-time graph for this model of the child's motion.
    \end{itemize}
    
    Using this model,
    \item calculate the total distance travelled by the child,
    \item find his final displacement from his original position.
    \end{enumerate}
    
    \hfill \mbox{\textit{OCR MEI Paper 1 2020 Q5 [5]}}