CAIE M1 2018 June — Question 5 8 marks

Exam BoardCAIE
ModuleM1 (Mechanics 1)
Year2018
SessionJune
Marks8
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicTravel graphs
TypeDisplacement-time graph interpretation or sketching
DifficultyModerate -0.8 This is a straightforward kinematics problem using constant acceleration equations and area under velocity-time graph. Part (i) requires basic SUVAT application (distance = ½×6×12 + 10×12 = 156m) and sketching a standard displacement-time curve. Part (ii) uses the remaining distance (44m) with trapezium area formula to find V=10. All steps are routine applications of standard mechanics formulas with no problem-solving insight required, making it easier than average but not trivial due to the multi-step nature.
Spec3.02b Kinematic graphs: displacement-time and velocity-time3.02c Interpret kinematic graphs: gradient and area

A sprinter runs a race of \(200 \text{ m}\). His total time for running the race is \(20 \text{ s}\). He starts from rest and accelerates uniformly for \(6 \text{ s}\), reaching a speed of \(12 \text{ m s}^{-1}\). He maintains this speed for the next \(10 \text{ s}\), before decelerating uniformly to cross the finishing line with speed \(V \text{ m s}^{-1}\).
  1. Find the distance travelled by the sprinter in the first \(16 \text{ s}\) of the race. Hence sketch a displacement-time graph for the \(20 \text{ s}\) of the sprinter's race. [6]
  2. Find the value of \(V\). [2]

Question 5:

AnswerMarks
5(i)1
[s = (0 + 12) × 6]
1
AnswerMarks Guidance
2M1 Use constant acceleration equations or
find area in (t,v) graph to find the distance
s travelled in the first 6 seconds
1
[s = 10 × 12]
AnswerMarks Guidance
2M1 Use constant acceleration equations or
find area in (t,v) graph to find s the
2
distance travelled between 6s and 16s
Distance for first 16s is
AnswerMarks
36 + 10 × 12 = 156A1
Curve concave up for 0 < t < 6
AnswerMarks Guidance
starting at (0 , 0) ending at (6 , 36)B1 Co-ordinates refer to (t,s) in a
displacement-time graph
Line, positive gradient, 6 < t < 16 starts at
AnswerMarks
(6 , 36) ends at (16 , 156)B1
Curve concave down, 16 < t < 20 from
AnswerMarks
(16 , 156) to (20 , 200)B1
6

AnswerMarks
5(ii)1
[44 = (12 + V) × 4]
AnswerMarks Guidance
2M1 Use relevant constant acceleration
equations or the area property of a v–t
graph
AnswerMarks
V = 10A1
2
AnswerMarks Guidance
QuestionAnswer Marks
Question 5:
--- 5(i) ---
5(i) | 1
[s = (0 + 12) × 6]
1
2 | M1 | Use constant acceleration equations or
find area in (t,v) graph to find the distance
s travelled in the first 6 seconds
1
[s = 10 × 12]
2 | M1 | Use constant acceleration equations or
find area in (t,v) graph to find s the
2
distance travelled between 6s and 16s
Distance for first 16s is
36 + 10 × 12 = 156 | A1
Curve concave up for 0 < t < 6
starting at (0 , 0) ending at (6 , 36) | B1 | Co-ordinates refer to (t,s) in a
displacement-time graph
Line, positive gradient, 6 < t < 16 starts at
(6 , 36) ends at (16 , 156) | B1
Curve concave down, 16 < t < 20 from
(16 , 156) to (20 , 200) | B1
6
--- 5(ii) ---
5(ii) | 1
[44 = (12 + V) × 4]
2 | M1 | Use relevant constant acceleration
equations or the area property of a v–t
graph
V = 10 | A1
2
Question | Answer | Marks | Guidance
A sprinter runs a race of $200 \text{ m}$. His total time for running the race is $20 \text{ s}$. He starts from rest and accelerates uniformly for $6 \text{ s}$, reaching a speed of $12 \text{ m s}^{-1}$. He maintains this speed for the next $10 \text{ s}$, before decelerating uniformly to cross the finishing line with speed $V \text{ m s}^{-1}$.

\begin{enumerate}[label=(\roman*)]
\item Find the distance travelled by the sprinter in the first $16 \text{ s}$ of the race. Hence sketch a displacement-time graph for the $20 \text{ s}$ of the sprinter's race. [6]
\item Find the value of $V$. [2]
\end{enumerate}

\hfill \mbox{\textit{CAIE M1 2018 Q5 [8]}}