Edexcel M1 2013 January — Question 4 9 marks

Exam BoardEdexcel
ModuleM1 (Mechanics 1)
Year2013
SessionJanuary
Marks9
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicFriction
TypePractical friction scenarios
DifficultyStandard +0.3 This is a standard M1 friction problem requiring resolution of forces on an inclined plane, application of F=μR, and use of equations of motion or energy methods. While it involves multiple steps (finding acceleration from kinematics, resolving forces parallel and perpendicular to plane, solving for μ), these are all routine techniques practiced extensively in M1. The 9-mark allocation reflects the working required rather than conceptual difficulty.
Spec3.02d Constant acceleration: SUVAT formulae3.03f Weight: W=mg3.03v Motion on rough surface: including inclined planes

A lifeboat slides down a straight ramp inclined at an angle of \(15°\) to the horizontal. The lifeboat has mass 800 kg and the length of the ramp is 50 m. The lifeboat is released from rest at the top of the ramp and is moving with a speed of 12.6 m s\(^{-1}\) when it reaches the end of the ramp. By modelling the lifeboat as a particle and the ramp as a rough inclined plane, find the coefficient of friction between the lifeboat and the ramp. [9]

AnswerMarks Guidance
\(12.6^2 = 2a.50\) \((\Rightarrow a = 1.5876)\)M1 A1
\(800g \sin 15 - F = 800a\)M1 A1
\(R = 800g \cos 15\)M1 A1
\(F = \mu R\)B1
\(800g \sin 15 - \mu 800g \cos 15 = 800 \times 1.5876\)M1
\(\mu = 0.1, 0.10, 0.100\)A1 (9)
Total for Question 4: 9
$12.6^2 = 2a.50$ $(\Rightarrow a = 1.5876)$ | M1 A1 |
$800g \sin 15 - F = 800a$ | M1 A1 |
$R = 800g \cos 15$ | M1 A1 |
$F = \mu R$ | B1 |
$800g \sin 15 - \mu 800g \cos 15 = 800 \times 1.5876$ | M1 |
$\mu = 0.1, 0.10, 0.100$ | A1 | (9)

**Total for Question 4: 9**

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A lifeboat slides down a straight ramp inclined at an angle of $15°$ to the horizontal. The lifeboat has mass 800 kg and the length of the ramp is 50 m. The lifeboat is released from rest at the top of the ramp and is moving with a speed of 12.6 m s$^{-1}$ when it reaches the end of the ramp. By modelling the lifeboat as a particle and the ramp as a rough inclined plane, find the coefficient of friction between the lifeboat and the ramp. [9]

\hfill \mbox{\textit{Edexcel M1 2013 Q4 [9]}}