Ans for AQA Physics P6 [ Summary Ans. ]

1. © Oxford University Press 2016 www.oxfordsecondary.co.uk/acknowledgements
This resource sheet may have been changed from the original. 1
P6 Summary answers
Student Book answers
Question
number
Answer Marks Guidance
1 a 2500 kg/m3
× 0.001 m3
= 2.5 kg
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1 b m = 2.5 kg + 0.32 kg = 2.8(2) kg
total weight = 2.8 kg × 10 N/kg = 28 N
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2 a 297 mm, 210 mm 1
2 b area = 0.297 m × 0.210 m = 0.0624 m2
or 624 cm2
mass = 80 g/ m2
× 0.0624 m2
= 5.0 g
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2 c 0.10 mm or 0.010 cm (= 50 mm/500) 1
2 d i volume = 624 cm2
× 0. 010 m = 6.24 cm3
density =
5.0 g
8.24
= 0.80 g/cm3
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2 d ii 800 kg/m3
as 1.0 g/cm3
= 1000 kg/m3
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3 a i solid from A to B as temperature increased towards its melting point as
energy supplied
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3 a ii melted from B to C as temperature did not change until all melted 1
3 a iii liquid from C to D as temperature increased as supplied with energy 1
3 b 78 °C 1
3 c A to B: particles in contact with each other and vibrate about fixed
positions, as temperature increases vibrations increase,
B to C: more particles break away from fixed positions to move at random,
C to D: particles all broken free and move about at random in contact with
each other
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4 a i 0.10 kg × 4200 J/kg/ °C × (18 – 3) °C
300 J
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2. © Oxford University Press 2016 www.oxfordsecondary.co.uk/acknowledgements
This resource sheet may have been changed from the original. 2
P6 Summary answers
Student Book answers
Question
number
Answer Marks Guidance
4 a ii 6300 J
450 s
= 14 J/s
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4 b i from 3 ºC to 0 ºC = 0.10 kg x 4 200 J/kg x (3 – 0) ºC
= 1 260J or 1.26 kJ
to freeze ΔE = 0.10 kg x 340 kJ/kg = 34 kJ or 34 000 J
total = 34 000 J + 1260 J = 35 260 J or 35.3 kJ
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4 b ii time taken at energy transfer rate of 14 J/s
=
35 260 J
14 J/s
= 2520 s or 42 minutes
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5 a 3 000 W x 30 s
= 90 000 J
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1
5 b 90 000 J
2300 000 J/kg
= 0.039 kg
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1
GCSE Physics only
6 a 120 000 Pa × 25 cm3
100 000 Pa
= 30 cm3
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3. © Oxford University Press 2016 www.oxfordsecondary.co.uk/acknowledgements
This resource sheet may have been changed from the original. 3
P6 Summary answers
Student Book answers
Question
number
Answer Marks Guidance
6 b pressure falls because internal energy of molecules decreases and
average speed decreases,
so collide less often with surface of container,
when they collide with surfaces , individual impacts exert less force on
surface,
so total force per unit area molecules exert on surface (i.e., gas pressure)
reduced
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7 a particles in gas move at random and average separation much greater
than in liquid or solid state,
for given number of particles, mass is same in each state whereas volume
occupied as gas much greater than in solid or liquid,
since density = mass/volume, density of a gas much less than density of
solid or liquid
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7 b particles in liquid move at random in contact with each other,
particles in solid hold each other together in fixed shape and vibrate about
mean positions,
when liquid cools and temperature falls, particles move slower,
until slow enough for forces of attraction between them to bond them
together in a fixed shape
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