CAIE M1 2012 November — Question 3 7 marks

Exam BoardCAIE
ModuleM1 (Mechanics 1)
Year2012
SessionNovember
Marks7
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicMotion on a slope
TypeString at angle to slope
DifficultyStandard +0.3 This is a standard M1 statics problem on an inclined plane with a force at an angle. It requires resolving forces in two directions (parallel and perpendicular to the plane) and applying equilibrium conditions, but follows a routine procedure with no novel insight needed. The given sin α simplifies calculations, and all three parts follow directly from standard force resolution—slightly easier than average due to its straightforward structure.
Spec3.03e Resolve forces: two dimensions3.03m Equilibrium: sum of resolved forces = 03.03t Coefficient of friction: F <= mu*R model

3 \includegraphics[max width=\textwidth, alt={}, center]{2bb3c9bb-60f0-440d-a148-b4db3478ca31-2_241_535_1247_806} A particle \(P\) of mass 0.5 kg rests on a rough plane inclined at angle \(\alpha\) to the horizontal, where \(\sin \alpha = 0.28\). A force of magnitude 0.6 N , acting upwards on \(P\) at angle \(\alpha\) from a line of greatest slope of the plane, is just sufficient to prevent \(P\) sliding down the plane (see diagram). Find
  1. the normal component of the contact force on \(P\),
  2. the frictional component of the contact force on \(P\),
  3. the coefficient of friction between \(P\) and the plane.

(i)
AnswerMarks Guidance
\([R + 0.6\sin \alpha = 0.5g \cos \alpha]\)M1 For resolving forces perpendicular to the plane
Normal component is 4.63(2) NA1 2
(ii)
AnswerMarks Guidance
\(F + 0.6\cos \alpha = 0.5g \sin \alpha\)M1 For resolving forces parallel to a line of greatest slope
A1
Frictional component is 0.824 NA1 3
(iii)
AnswerMarks Guidance
\(\mu = F/R\)M1 For using \(\mu = F/R\)
Coefficient is 0.178A1 ft 2
**(i)**
$[R + 0.6\sin \alpha = 0.5g \cos \alpha]$ | M1 | For resolving forces perpendicular to the plane
Normal component is 4.63(2) N | A1 | 2

**(ii)**
$F + 0.6\cos \alpha = 0.5g \sin \alpha$ | M1 | For resolving forces parallel to a line of greatest slope
| A1 |
Frictional component is 0.824 N | A1 | 3

**(iii)**
$\mu = F/R$ | M1 | For using $\mu = F/R$
Coefficient is 0.178 | A1 ft | 2
3\\
\includegraphics[max width=\textwidth, alt={}, center]{2bb3c9bb-60f0-440d-a148-b4db3478ca31-2_241_535_1247_806}

A particle $P$ of mass 0.5 kg rests on a rough plane inclined at angle $\alpha$ to the horizontal, where $\sin \alpha = 0.28$. A force of magnitude 0.6 N , acting upwards on $P$ at angle $\alpha$ from a line of greatest slope of the plane, is just sufficient to prevent $P$ sliding down the plane (see diagram). Find\\
(i) the normal component of the contact force on $P$,\\
(ii) the frictional component of the contact force on $P$,\\
(iii) the coefficient of friction between $P$ and the plane.

\hfill \mbox{\textit{CAIE M1 2012 Q3 [7]}}