CAIE M2 2014 June — Question 7

Exam BoardCAIE
ModuleM2 (Mechanics 2)
Year2014
SessionJune
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicCentre of Mass 1
TypeComposite solid with hemisphere and cylinder/cone
DifficultyStandard +0.3 This is a standard centre of mass question requiring application of the formula for composite bodies made of uniform laminas. While it involves multiple shapes (rectangle and triangle) and requires careful coordinate setup, the method is routine and well-practiced in M2. The multi-part structure guides students through the solution systematically, making it slightly easier than average.

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Question 7:

AnswerMarks
7 (i)T = 42m(0.5 – 0.4) / 0.4
10m = Y + T × (0.3 / 0.5)
AnswerMarks
Y = 3.7m AGB1
M1
AnswerMarks Guidance
A13 T = 10.5m
(ii)2
mω ×0.4=T×(0.4/0.5)
AnswerMarks Guidance
ω =4.58rads−1M1
A12 ft cv of T
Page 6Mark Scheme Syllabus
GCE A LEVEL – May/June 20149709 52
( iii)mv 2 /0.4=T × (0.4/0.5)±2m
–1
v = 2.04 ms
–1
AnswerMarks
or v = 1.6 msM1
A1
AnswerMarks Guidance
A13 Either case
(iv)Y = 10m
2
10m=mv /0.4
–1
AnswerMarks
v = 2 msB1
M1
AnswerMarks Guidance
A13 Fresh value of Y not Y(i)
Reject or ignore –2
Question 7:
--- 7 (i) ---
7 (i) | T = 42m(0.5 – 0.4) / 0.4
10m = Y + T × (0.3 / 0.5)
Y = 3.7m AG | B1
M1
A1 | 3 | T = 10.5m
(ii) | 2
mω ×0.4=T×(0.4/0.5)
ω =4.58rads−1 | M1
A1 | 2 | ft cv of T
Page 6 | Mark Scheme | Syllabus | Paper
GCE A LEVEL – May/June 2014 | 9709 | 52
( iii) | mv 2 /0.4=T × (0.4/0.5)±2m
–1
v = 2.04 ms
–1
or v = 1.6 ms | M1
A1
A1 | 3 | Either case
(iv) | Y = 10m
2
10m=mv /0.4
–1
v = 2 ms | B1
M1
A1 | 3 | Fresh value of Y not Y(i)
Reject or ignore –2
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\hfill \mbox{\textit{CAIE M2 2014 Q7}}