CAIE FP2 2012 November — Question 1 4 marks

Exam BoardCAIE
ModuleFP2 (Further Pure Mathematics 2)
Year2012
SessionNovember
Marks4
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicCircular Motion 2
TypeAngular speed and period
DifficultyChallenging +1.2 This is a Further Maths mechanics question requiring knowledge of radial and transverse acceleration components in circular motion. Students must recall that radial acceleration is v²/r and transverse acceleration is dv/dt, set them equal using the given velocity function, and solve a quadratic equation. While it involves multiple steps and FM content, the approach is relatively standard once the formulas are identified.
Spec6.05e Radial/tangential acceleration

1 A particle \(P\) is moving in a circle of radius 1.5 m . At time \(t \mathrm {~s}\) its velocity is \(\left( k - t ^ { 2 } \right) \mathrm { m } \mathrm { s } ^ { - 1 }\), where \(k\) is a positive constant. When \(t = 3\), the magnitudes of the radial and transverse components of the acceleration of \(P\) are equal. Find the possible values of \(k\).

Question 1:
AnswerMarks Guidance
Answer/WorkingMarks Guidance
Radial acceleration when \(t=3\): \((k-3^2)^2/1.5\) \([\text{m s}^{-2}]\)B1
Transverse accel. (ignoring sign) when \(t=3\): \(2t=6\) \([\text{m s}^{-2}]\)B1
Equate magnitudes to find \(k\): \((k-9)^2=9\), \(k=6\) or \(12\)M1 A1 Total: [4]
## Question 1:
| Answer/Working | Marks | Guidance |
|---|---|---|
| Radial acceleration when $t=3$: $(k-3^2)^2/1.5$ $[\text{m s}^{-2}]$ | B1 | |
| Transverse accel. (ignoring sign) when $t=3$: $2t=6$ $[\text{m s}^{-2}]$ | B1 | |
| Equate magnitudes to find $k$: $(k-9)^2=9$, $k=6$ or $12$ | M1 A1 | Total: [4] |

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1 A particle $P$ is moving in a circle of radius 1.5 m . At time $t \mathrm {~s}$ its velocity is $\left( k - t ^ { 2 } \right) \mathrm { m } \mathrm { s } ^ { - 1 }$, where $k$ is a positive constant. When $t = 3$, the magnitudes of the radial and transverse components of the acceleration of $P$ are equal. Find the possible values of $k$.

\hfill \mbox{\textit{CAIE FP2 2012 Q1 [4]}}