CAIE M1 2017 March — Question 2 6 marks

Exam BoardCAIE
ModuleM1 (Mechanics 1)
Year2017
SessionMarch
Marks6
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicForces, equilibrium and resultants
TypeParticle suspended by strings
DifficultyModerate -0.8 This is a standard two-string equilibrium problem requiring resolution of forces in two directions and solving simultaneous equations. It's straightforward application of basic statics with no conceptual challenges—easier than average but not trivial due to the calculation steps involved.
Spec3.03e Resolve forces: two dimensions3.03m Equilibrium: sum of resolved forces = 0

\includegraphics{figure_2} A particle \(P\) of mass \(1.6\) kg is suspended in equilibrium by two light inextensible strings attached to points \(A\) and \(B\). The strings make angles of \(20°\) and \(40°\) respectively with the horizontal (see diagram). Find the tensions in the two strings. [6]

Question 2:
AnswerMarks Guidance
2M1 Resolve forces horizontally
and/or vertically
T sin 20 + T sin 40 = 16
AnswerMarks Guidance
A BA1 Correct vertical equation
T cos 20 = T cos 40
AnswerMarks Guidance
A BA1 Correct horizontal equation
M1Attempt to solve for T and/or T
A B
T = 14.2N
AnswerMarks Guidance
AA1 T = 14.1528...
A
T = 17.4N
AnswerMarks Guidance
BA1 T = 17.3610...
B
AnswerMarks
Total:6
Alternative method for Question 2
AnswerMarks
M1Attempt to use Lami’s Theorem
16 T
= A
AnswerMarks
sin120 sin130A1
16 T
= B
AnswerMarks
sin120 sin110A1
M1Attempt to solve for T and/or T
A B
T = 14.2N
AnswerMarks
AA1
T = 17.4N
AnswerMarks Guidance
BA1
Total:6
QuestionAnswer Marks
Question 2:
2 | M1 | Resolve forces horizontally
and/or vertically
T sin 20 + T sin 40 = 16
A B | A1 | Correct vertical equation
T cos 20 = T cos 40
A B | A1 | Correct horizontal equation
M1 | Attempt to solve for T and/or T
A B
T = 14.2N
A | A1 | T = 14.1528...
A
T = 17.4N
B | A1 | T = 17.3610...
B
Total: | 6
Alternative method for Question 2
M1 | Attempt to use Lami’s Theorem
16 T
= A
sin120 sin130 | A1
16 T
= B
sin120 sin110 | A1
M1 | Attempt to solve for T and/or T
A B
T = 14.2N
A | A1
T = 17.4N
B | A1
Total: | 6
Question | Answer | Marks | Guidance
\includegraphics{figure_2}

A particle $P$ of mass $1.6$ kg is suspended in equilibrium by two light inextensible strings attached to points $A$ and $B$. The strings make angles of $20°$ and $40°$ respectively with the horizontal (see diagram). Find the tensions in the two strings. [6]

\hfill \mbox{\textit{CAIE M1 2017 Q2 [6]}}