AQA GCSE Physics Physics Paper 1 (Higher), June 2022: Question 2

10 marks · Standard Demand difficulty · Extended Answer

Describe a method to determine the density of an irregular rock, calculate its maximum and minimum density values from an uncertainty range, identify the rock type using a density table, and explain why repeating measurements improves accuracy.

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Question

Question text

02 Figure 2 shows a rock found by a student on a beach.

To help identify the type of rock, the student took measurements to determine

its density.

Figure 2

02.1 Describe a method the student could use to determine the density of the rock.

[6 marks]

The student determined the density of the rock to be 2.55 ± 0.10 g/cm3.

02.2 What are the maximum and minimum values for the density of the rock?

*04* [1 mark]

Maximum density = g/cm3

Minimum density = g/cm3

02.3 Table 1 gives the density of five different types of rock.

Table 1

Type of rock Density in g/cm3

Basalt 2.90 ± 0.10

Chalk 2.35 ± 0.15

Flint 2.60 ± 0.10

Sandstone 2.20 ± 0.20

Slate 2.90 ± 0.20

Which two types of rock in Table 1 could be the type of rock the student had?

[1 mark]

Tick ( ) one box.

Basalt or chalk

Chalk or flint

Flint or sandstone

Sandstone or slate 6

02.4 The student only took one set of measurements to determine the density of the rock.

Explain why taking the measurements more than once may improve the accuracy of

the density value.

[2 marks]

Mark scheme

Show the mark scheme

AO /

Question Answers Mark

Spec. Ref.

02.1 Level 3: The method would lead to the production of a valid 5–6 AO1

outcome. All key steps are identified and logically sequenced. 4.3.1.1

RPA5

Level 2: The method would not necessarily lead to a valid 3–4

outcome. Most steps are identified, but the method is not fully

logically sequenced.

Level 1: The method would not lead to a valid outcome. Some 1–2

relevant steps are identified, but links are not made clear.

No relevant content 0

Indicative content:

• measure mass using a balance / scales

• part fill a measuring cylinder with water and measure initial

volume

• place rock in water and measure final volume

• volume of rock = final volume − initial volume

• fill a displacement / eureka can with water level with spout

• place rock in water and collect displaced water

• measuring cylinder used to determine volume of displaced water

• volume of rock = volume of displaced water

•

• use mass and volume to calculate density

mass

● use of: density =

volume

AO /

Question Answers Extra information Mark

Spec. Ref.

02.2 maximum density = 2.65 (g/cm3) both required 1 AO3

4.3.1.1

minimum density = 2.45 (g/cm3) RPA5

– HYSICS – –

AO /

Spec. Ref.

02.3 chalk or flint 1 AO3 9

4.3.1.1

RPA5

AO /

Spec. Ref.

02.4 a mean can be calculated 1 AO3

4.3.1.1

which reduces the effect of allow anomalies can be 1 RPA5

random errors identified / removed

– HYSICS – –

Total Question 2 10

Question 3

How to answer it

Determining the Density of an Irregular Object

AQA GCSE Physics • Required Practical 5 (Density)

What this question tests

This question assesses your knowledge of Required Practical 5 (density of irregular objects), the ability to interpret measurement uncertainties, compare experimental data against standard reference tables, and understand how repeated measurements improve accuracy and reduce random errors.

Part (02.1): Describing the Method

Describe a method the student could use to determine the density of the rock. [6 marks]

💡 Key Knowledge (Required Practical)

Mass: Measure mass using a digital balance / scales.
Volume (Method A): Part-fill a measuring cylinder with water, record initial volume, submerge the rock, record final volume. Volume equals final minus initial.
Volume (Method B): Fill a displacement (Eureka) can until water drips from the spout, place a measuring cylinder underneath, submerge the rock, and measure the displaced water volume.
Calculation: Use the formula density = mass ÷ volume .

🧠 Exam Technique (6-Mark Level of Response)

To hit Level 3 (5–6 marks), your answer must be a logical, step-by-step procedure that would successfully yield a valid density value.
Write in full, continuous prose or clear numbered steps. Do not miss out the crucial step of calculating density at the end!

❌ Common Errors & Examiner Commentary

Students often lose marks by forgetting to explain how to find the volume of an irregular object (e.g., just saying "put it in a measuring cylinder" without mentioning water levels). Another frequent error is measuring water level wrongly by reading the top of the meniscus instead of the bottom.

Part (02.2): Uncertainty Calculations

What are the maximum and minimum values for the density of the rock? [1 mark]

Given measured density: 2.55 ± 0.10 g/cm³

✅ Correct Answers

Maximum density = 2.65 g/cm³
Minimum density = 2.45 g/cm³

Both values required for the 1 mark.

📐 Calculation Steps

Maximum: Add the uncertainty to the measured value ( 2.55 + 0.10 = 2.65 ).
Minimum: Subtract the uncertainty from the measured value ( 2.55 - 0.10 = 2.45 ).

Part (02.3): Identifying the Rock

Which two types of rock in Table 1 could be the type of rock the student had? Tick one box. [1 mark]

✅ Correct Answer

Chalk or flint (Tick the second box)

Examiner Insight: Students had to cross-reference their calculated range (2.45 to 2.65 g/cm³) with the ranges given in Table 1. Only Chalk ( 2.35 ± 0.15 gives a range of 2.20 to 2.50) and Flint ( 2.60 ± 0.10 gives 2.50 to 2.70) overlap with the student's measured range.

❌ Common Errors

Guessing based on the nominal table values alone without factoring in the ± tolerances provided in Table 1.

Part (02.4): Improving Accuracy

Explain why taking the measurements more than once may improve the accuracy of the density value. [2 marks]

✅ Correct Answers (Mark Scheme)

A mean can be calculated ( 1 mark )
...which reduces the effect of random errors / allows anomalies to be identified and removed ( 1 mark )

🧠 Examiner Commentary

Top-level responses explicitly linked repetition to calculating a mean and explaining the consequence (minimising random variation). Vague statements like "to make it more accurate" without explaining *how* repetition helps will not score the second mark.

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), June 2022. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.