CAIE M1 2003 November — Question 5 7 marks

Exam BoardCAIE
ModuleM1 (Mechanics 1)
Year2003
SessionNovember
Marks7
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicPulley systems
TypeParticle on rough horizontal surface, particle hanging
DifficultyModerate -0.3 This is a standard two-particle pulley system problem requiring Newton's second law applied to both particles, solving simultaneous equations for tension and acceleration, then using constant acceleration kinematics. While it involves multiple steps and careful sign conventions, it follows a well-established method taught in M1 with no novel insight required. The friction component is straightforward. Slightly easier than average due to being a textbook application.
Spec3.03o Advanced connected particles: and pulleys

5 \includegraphics[max width=\textwidth, alt={}, center]{5cba3e17-3979-4c22-a415-2cdd60f09289-3_300_792_274_680} Particles \(A\) and \(B\), of masses 0.4 kg and 0.1 kg respectively, are attached to the ends of a light inextensible string. Particle \(A\) is held at rest on a horizontal table with the string passing over a smooth pulley at the edge of the table. Particle \(B\) hangs vertically below the pulley (see diagram). The system is released from rest. In the subsequent motion a constant frictional force of magnitude 0.6 N acts on \(A\). Find
  1. the tension in the string,
  2. the speed of \(B 1.5 \mathrm {~s}\) after it starts to move.

AnswerMarks Guidance
For applying Newton's second law to A or to B (3 terms needed)M1
\(T - 0.6 = 0.4a\) or \(0.1g - T = 0.1a\)A1
For a second of the above 2 equations or for \(0.1g - 0.6 = 0.5a\)B1 (Can be scored in part (ii))
(Sign of a must be consistent with that in first equation)
Tension is 0.92 NA1 4 marks
\(a = 0.8\)B1
For using \(v = at\)M1
Speed = 1.2 m s\(^{-1}\)A1 3 marks
For applying Newton's second law to A or to B (3 terms needed) | M1 |
$T - 0.6 = 0.4a$ or $0.1g - T = 0.1a$ | A1 |
For a second of the above 2 equations or for $0.1g - 0.6 = 0.5a$ | B1 | (Can be scored in part (ii))
(Sign of a must be consistent with that in first equation) |  |
Tension is 0.92 N | A1 | 4 marks

$a = 0.8$ | B1 |

For using $v = at$ | M1 |
Speed = 1.2 m s$^{-1}$ | A1 | 3 marks

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5\\
\includegraphics[max width=\textwidth, alt={}, center]{5cba3e17-3979-4c22-a415-2cdd60f09289-3_300_792_274_680}

Particles $A$ and $B$, of masses 0.4 kg and 0.1 kg respectively, are attached to the ends of a light inextensible string. Particle $A$ is held at rest on a horizontal table with the string passing over a smooth pulley at the edge of the table. Particle $B$ hangs vertically below the pulley (see diagram). The system is released from rest. In the subsequent motion a constant frictional force of magnitude 0.6 N acts on $A$. Find\\
(i) the tension in the string,\\
(ii) the speed of $B 1.5 \mathrm {~s}$ after it starts to move.

\hfill \mbox{\textit{CAIE M1 2003 Q5 [7]}}