OCR M1 2010 January — Question 6 12 marks

Exam BoardOCR
ModuleM1 (Mechanics 1)
Year2010
SessionJanuary
Marks12
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicVariable acceleration (1D)
TypeDisplacement from velocity by integration
DifficultyStandard +0.3 This is a straightforward calculus-based mechanics problem requiring differentiation to find acceleration, using the minimum condition (dv/dt = 0) to find k, and integration to find distance. All steps are standard M1 techniques with no novel problem-solving required, making it slightly easier than average.
Spec3.02d Constant acceleration: SUVAT formulae

6 A swimmer \(C\) swims with velocity \(v \mathrm {~ms} ^ { - 1 }\) in a swimming pool. At time \(t \mathrm {~s}\) after starting, \(v = 0.006 t ^ { 2 } - 0.18 t + k\), where \(k\) is a constant. \(C\) swims from one end of the pool to the other in 28.4 s .
  1. Find the acceleration of \(C\) in terms of \(t\).
  2. Given that the minimum speed of \(C\) is \(0.65 \mathrm {~m} \mathrm {~s} ^ { - 1 }\), show that \(k = 2\).
  3. Express the distance travelled by \(C\) in terms of \(t\), and calculate the length of the pool.

6 A swimmer $C$ swims with velocity $v \mathrm {~ms} ^ { - 1 }$ in a swimming pool. At time $t \mathrm {~s}$ after starting, $v = 0.006 t ^ { 2 } - 0.18 t + k$, where $k$ is a constant. $C$ swims from one end of the pool to the other in 28.4 s .\\
(i) Find the acceleration of $C$ in terms of $t$.\\
(ii) Given that the minimum speed of $C$ is $0.65 \mathrm {~m} \mathrm {~s} ^ { - 1 }$, show that $k = 2$.\\
(iii) Express the distance travelled by $C$ in terms of $t$, and calculate the length of the pool.

\hfill \mbox{\textit{OCR M1 2010 Q6 [12]}}