Q23 · 2024 · Paper 1Simple familiar4 marks
QUESTION 23 (4 marks)
An experiment was conducted to study an object undergoing circular motion, with the radius of motion acting as the independent variable and the speed kept constant. The data comparing the period and radius of motion is shown.
a)[1 mark]
Identify the period expected for a radius of motion.
b)[3 marks]
Determine the constant speed of the object. Show your working.
WORKED SOLUTION
4 marksQCAA guide · typeset solution
ANSWER
See worked solution below.
Worked solution
Period = 0.21 s
2
1
2
1
1
gradient
0.40
0.10
0.50
0.10
0.30
0.40
s m
(to two significant figures)
0.75
y
y
x
x
−
=
−
−
−
=
−
=
=
2
2
Since
, then
, therefore
2
gradient
v
r
r
v
T
T
v
π
π
π
=
=
=
2
0.75
8.38
v
v
π
=
=
Speed = 8.38 m s–1
• identifies the period [1 mark]
• calculates gradient [1 mark]
• recognises the relationship between
gradient and average speed (i.e.
2
m
v
π
=
)
[1 mark]
• determines the constant speed of the object
[1 mark]
One QCAA sample method typeset for web; criterion wording is adapted from the official marking guide.
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Compare your working with the guide above.