AQA GCSE Physics Physics Paper 1 (Higher), November 2021: Question 4
6 marks · Low Demand difficulty · Short Answer
Identify equipment, state the formula, calculate the volume of an apple given its density and mass, and explain why repeat measurements are needed to show precision when measuring fruit density.
Practise this questionQuestion
Question text
04 A student investigated the density of different fruits.
Table 1 shows the results.
Table 1
Fruit Density in g/cm3
Apple 0.68
Kiwi 1.03
Lemon 0.95
Lime 1.05
04.1 The student determined the volume of each fruit using a displacement can and a
measuring cylinder.
What other piece of equipment would the student need to determine the density of
each fruit?
[1 mark]
04.2 Write down the equation which links density (ρ), mass (m) and volume (V).
[1 mark]
04.3 The mass of the apple was 85 g.
The density of the apple was 0.68 g/cm3.
Calculate the volume of the apple.
Give your answer in cm3.
[3 marks]
Volume = cm3
04.4 The student only measured the volume of each fruit once.
The volume measurements cannot be used to show that the method to measure
volume gives precise readings.
Give the reason why.
[1 mark]
05.1 During one year, 1.25 × 1018 J of energy was transferred from the National Grid.
number of seconds in 1 year = 3.16 × 107
Calculate the mean energy transferred from the National Grid each second.
Give your answer to 3 significant figures.
[2 marks]
Energy each second (3 significant figures) = J
Figure 5 shows a house with a solar power system.
The solar cells generate electricity.
When the electricity generated by the solar cells is not needed, the energy is stored in
a large battery.
Figure 5
Mark scheme
Show the mark scheme
Question 4
AO /
Question Answers Extra information Mark
Spec. Ref.
04.1 balance / scales 1 AO1
4.3.1.1
RPA5
mass
04.2 density = 1 AO1
volume
4.3.1.1
or RPA5
m
ρ =
V
04.3 85 1 AO2
0.68 = 4.3.1.1
V
85 RPA5
V = 1
0.68
V = 125 (cm )
04.4 repeat readings (of volume) 1 AO3
need taking (of each fruit) to 4.3.1.1
show that the readings are close allow ‘the same’ for ‘close RPA5
together together’
Total 6
How to answer it
Density of Irregular Objects (Required Practical 5)
This question evaluates your foundational knowledge of AQA GCSE Physics Topic 3 (Particle Model of Matter) and Required Practical 5 (Determining Densities):
- Identifying laboratory apparatus required to measure mass.
- Recalling the standard formula linking density, mass, and volume.
- Rearranging an algebraic formula to calculate an unknown volume.
- Understanding scientific working terms, specifically what is required to demonstrate precision in experimental measurements.
Measuring Mass of Irregular Objects
Apparatus for determining density
✅ Correct Answer
Balance (or scales / electronic top-pan balance).
💡 Key Knowledge
Density depends on two quantities: mass and volume.
- Volume of irregular objects is measured by water displacement (displacement can + measuring cylinder).
- Mass must always be measured using a balance.
❌ Common Errors
- Writing "weighing scale" or "weight machine" — in Physics, use the precise term balance.
- Confusing mass with weight (a newtonmeter measures weight in N, not mass).
🧠 Exam Technique
Always pair the property being measured with its standard apparatus:
- Length → Ruler / Callipers
- Volume → Measuring cylinder
- Mass → Balance
Density Formula Recall
Linking density (ρ), mass (m), and volume (V)
✅ Correct Answer
density = mass / volume
or in symbols:
ρ = m / V
🧠 Exam Technique
When asked to "Write down the equation...", you must state it in its direct form, word form, or using standard accepted symbols. Do not write a rearranged form (e.g. m = ρ × V) unless prompted, as writing the root equation is always safer.
❌ Common Errors
- Inverting the ratio: writing density = volume / mass (0 marks).
- Confusing the Greek symbol rho ( ρ ) with lower case letter p (momentum or pressure). If in doubt, write the word equation!
Calculating Volume from Mass and Density
Rearranging equations and substituting values
📐 Step-by-Step Calculation
Given: Mass m = 85 g , Density ρ = 0.68 g/cm³
- Step 1: Substitute the values into the formula [1 mark]
0.68 = 85 / V - Step 2: Rearrange to make V the subject [1 mark]
Multiply by V: 0.68 × V = 85
Divide by 0.68: V = 85 / 0.68 - Step 3: Calculate the numerical value [1 mark]
V = 125 cm³
✅ Final Answer
125 cm³
Units are already provided in the question line, so just the number was required.
❌ Common Traps
- Rearrangement trap: Students often multiply the numbers instead ( 85 × 0.68 = 57.8 ), which scores 0 marks.
- Unit conversion panic: Notice the units are already compatible: mass in g and density in g/cm³ directly yield volume in cm³ . Do not convert to kg or m³ unless specifically requested!
Evaluating Precision in Practical Work
Working Scientifically: Repeated measurements
✅ Correct Answer
Repeat readings (of volume) must be taken (for each fruit) to show that the readings are close together (or "the same").
💡 Key Knowledge: Definition of Precision
- Precise measurements: Readings that have very little spread about the mean value (i.e., repeated readings are close together).
- Accurate measurements: Readings that are close to the true value.
- You cannot determine precision from a single measurement because you have no other values to compare it with!
❌ Common Errors
- Stating "to find an average" or "to identify anomalies" — while true for repeating experiments, this does not explain why you cannot judge precision.
- Confusing precision with accuracy (e.g. saying "it doesn't show it's close to the real value").
- Vague answers such as "they only did it once" without mentioning that repeats are needed to check if readings agree or are close together.
🧠 Exam Technique
Whenever a question asks why a single measurement cannot show precision, the answer must link two ideas:
- You need repeats.
- To see if the results are close together / concordant.
Topics
Physics · Required Practicals · P3: Particle Model of Matter · Required Practicals
Question and mark scheme from the AQA GCSE Physics examination, Physics Paper 1 (Higher), November 2021. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.