CAIE M1 2003 June — Question 4 6 marks

Exam BoardCAIE
ModuleM1 (Mechanics 1)
Year2003
SessionJune
Marks6
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicVariable acceleration (1D)
TypeVelocity from displacement differentiation
DifficultyModerate -0.8 This is a straightforward differentiation exercise requiring only basic calculus rules (power rule applied twice) and simple algebraic manipulation. The question tests routine application of v = dx/dt and a = dv/dt with no problem-solving insight needed, making it easier than average for A-level mechanics.
Spec1.07b Gradient as rate of change: dy/dx notation1.07i Differentiate x^n: for rational n and sums3.02a Kinematics language: position, displacement, velocity, acceleration

4 A particle moves in a straight line. Its displacement \(t\) seconds after leaving the fixed point \(O\) is \(x\) metres, where \(x = \frac { 1 } { 2 } t ^ { 2 } + \frac { 1 } { 30 } t ^ { 3 }\). Find
  1. the speed of the particle when \(t = 10\),
  2. the value of \(t\) for which the acceleration of the particle is twice its initial acceleration.

Question 4:
Part (i)
AnswerMarks
For differentiating \(x\)M1
\(\dot{x} = t + \frac{1}{10}t^2\)A1
Speed is 20 ms\(^{-1}\)A1
Part (ii)
AnswerMarks
\(\ddot{x} = 1 + \frac{1}{5}t\)B1ft
For attempting to solve \(\ddot{x}(t) = 2\ddot{x}(0)\) \(\left(1 + \frac{1}{5}t = 2\right)\)M1
\(t = 5\)A1
# Question 4:

## Part (i)
| For differentiating $x$ | M1 | |
| $\dot{x} = t + \frac{1}{10}t^2$ | A1 | |
| Speed is 20 ms$^{-1}$ | A1 | |

## Part (ii)
| $\ddot{x} = 1 + \frac{1}{5}t$ | B1ft | |
| For attempting to solve $\ddot{x}(t) = 2\ddot{x}(0)$ $\left(1 + \frac{1}{5}t = 2\right)$ | M1 | |
| $t = 5$ | A1 | |

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4 A particle moves in a straight line. Its displacement $t$ seconds after leaving the fixed point $O$ is $x$ metres, where $x = \frac { 1 } { 2 } t ^ { 2 } + \frac { 1 } { 30 } t ^ { 3 }$. Find\\
(i) the speed of the particle when $t = 10$,\\
(ii) the value of $t$ for which the acceleration of the particle is twice its initial acceleration.

\hfill \mbox{\textit{CAIE M1 2003 Q4 [6]}}