CAIE M1 2004 November — Question 7 10 marks

Exam BoardCAIE
ModuleM1 (Mechanics 1)
Year2004
SessionNovember
Marks10
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicVariable acceleration (1D)
TypeMaximum or minimum velocity
DifficultyStandard +0.3 This is a straightforward non-constant acceleration problem requiring standard calculus techniques: factorizing a cubic to find when v=0, integrating velocity to find distance, and differentiating to find maximum velocity. All steps are routine applications of A-level methods with no conceptual challenges, making it slightly easier than average.
Spec1.08d Evaluate definite integrals: between limits3.02f Non-uniform acceleration: using differentiation and integration3.02g Two-dimensional variable acceleration

7 A particle starts from rest at the point \(A\) and travels in a straight line until it reaches the point \(B\). The velocity of the particle \(t\) seconds after leaving \(A\) is \(v \mathrm {~m} \mathrm {~s} ^ { - 1 }\), where \(v = 0.009 t ^ { 2 } - 0.0001 t ^ { 3 }\). Given that the velocity of the particle when it reaches \(B\) is zero, find
  1. the time taken for the particle to travel from \(A\) to \(B\),
  2. the distance \(A B\),
  3. the maximum velocity of the particle.

Question 7:
Part (i):
AnswerMarks Guidance
Answer/WorkingMark Guidance
\(t^2(0.009 - 0.0001t) = 0\)M1 For attempting to solve \(v(t) = 0\) for \(t \neq 0\)
Time is \(90 \text{ s}\)A1 2 marks total
Part (ii):
AnswerMarks Guidance
Answer/WorkingMark Guidance
M1For attempting to integrate \(v(t)\)
\(s = 0.003t^3 - 0.000025t^4 \quad (+C)\)A1
\((2187 - 1640.25) - (0 - 0)\)M1 For attempting to find \(s(\text{ans i}) - s(0)\) [the subtraction of \(s(0)\) is implied if \(C\) is found to be zero or if \(C\) is absent]
Distance is \(547 \text{ m}\)A1 4 marks total
Part (iii):
AnswerMarks Guidance
Answer/WorkingMark Guidance
\(0.018t - 0.0003t^2 = 0 \rightarrow t(0.018 - 0.0003t) = 0\)M1 For obtaining \(\dot{v}\) and attempting to solve \(\dot{v} = 0\)
\(t = 60\) (may be implied)A1
\(32.4 - 21.6\)M1 For attempting to find \(v(60)\)
Maximum speed is \(10.8 \text{ ms}^{-1}\)A1 4 marks total
# Question 7:

## Part (i):
| Answer/Working | Mark | Guidance |
|---|---|---|
| $t^2(0.009 - 0.0001t) = 0$ | M1 | For attempting to solve $v(t) = 0$ for $t \neq 0$ |
| Time is $90 \text{ s}$ | A1 | **2 marks total** |

## Part (ii):
| Answer/Working | Mark | Guidance |
|---|---|---|
| | M1 | For attempting to integrate $v(t)$ |
| $s = 0.003t^3 - 0.000025t^4 \quad (+C)$ | A1 | |
| $(2187 - 1640.25) - (0 - 0)$ | M1 | For attempting to find $s(\text{ans i}) - s(0)$ [the subtraction of $s(0)$ is implied if $C$ is found to be zero or if $C$ is absent] |
| Distance is $547 \text{ m}$ | A1 | **4 marks total** |

## Part (iii):
| Answer/Working | Mark | Guidance |
|---|---|---|
| $0.018t - 0.0003t^2 = 0 \rightarrow t(0.018 - 0.0003t) = 0$ | M1 | For obtaining $\dot{v}$ and attempting to solve $\dot{v} = 0$ |
| $t = 60$ (may be implied) | A1 | |
| $32.4 - 21.6$ | M1 | For attempting to find $v(60)$ |
| Maximum speed is $10.8 \text{ ms}^{-1}$ | A1 | **4 marks total** |
7 A particle starts from rest at the point $A$ and travels in a straight line until it reaches the point $B$. The velocity of the particle $t$ seconds after leaving $A$ is $v \mathrm {~m} \mathrm {~s} ^ { - 1 }$, where $v = 0.009 t ^ { 2 } - 0.0001 t ^ { 3 }$. Given that the velocity of the particle when it reaches $B$ is zero, find\\
(i) the time taken for the particle to travel from $A$ to $B$,\\
(ii) the distance $A B$,\\
(iii) the maximum velocity of the particle.

\hfill \mbox{\textit{CAIE M1 2004 Q7 [10]}}