CAIE M1 2014 June — Question 4

Exam BoardCAIE
ModuleM1 (Mechanics 1)
Year2014
SessionJune
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicVariable acceleration (1D)
TypePiecewise motion functions
DifficultyStandard +0.3 This is a straightforward two-phase kinematics problem requiring basic differentiation of v = ½t^(2/3) to find acceleration, comparison of accelerations at t=8, and integration/SUVAT application to find distance. The calculations are routine for M1 level with no conceptual challenges beyond standard variable acceleration techniques.
Spec1.07a Derivative as gradient: of tangent to curve1.08d Evaluate definite integrals: between limits3.02f Non-uniform acceleration: using differentiation and integration

4 A particle \(P\) moves on a straight line, starting from rest at a point \(O\) of the line. The time after \(P\) starts to move is \(t \mathrm {~s}\), and the particle moves along the line with constant acceleration \(\frac { 1 } { 4 } \mathrm {~m} \mathrm {~s} ^ { - 2 }\) until it passes through a point \(A\) at time \(t = 8\). After passing through \(A\) the velocity of \(P\) is \(\frac { 1 } { 2 } t ^ { \frac { 2 } { 3 } } \mathrm {~m} \mathrm {~s} ^ { - 1 }\).
  1. Find the acceleration of \(P\) immediately after it passes through \(A\). Hence show that the acceleration of \(P\) decreases by \(\frac { 1 } { 12 } \mathrm {~m} \mathrm {~s} ^ { - 2 }\) as it passes through \(A\).
  2. Find the distance moved by \(P\) from \(t = 0\) to \(t = 27\).

4 A particle $P$ moves on a straight line, starting from rest at a point $O$ of the line. The time after $P$ starts to move is $t \mathrm {~s}$, and the particle moves along the line with constant acceleration $\frac { 1 } { 4 } \mathrm {~m} \mathrm {~s} ^ { - 2 }$ until it passes through a point $A$ at time $t = 8$. After passing through $A$ the velocity of $P$ is $\frac { 1 } { 2 } t ^ { \frac { 2 } { 3 } } \mathrm {~m} \mathrm {~s} ^ { - 1 }$.\\
(i) Find the acceleration of $P$ immediately after it passes through $A$. Hence show that the acceleration of $P$ decreases by $\frac { 1 } { 12 } \mathrm {~m} \mathrm {~s} ^ { - 2 }$ as it passes through $A$.\\
(ii) Find the distance moved by $P$ from $t = 0$ to $t = 27$.

\hfill \mbox{\textit{CAIE M1 2014 Q4}}