AQA GCSE Physics Physics Paper 2 (Higher), June 2024: Question 2
14 marks · Standard Demand difficulty · Short Answer
Analyze forces, work done, moments, and motion involving a young child using a baby walker with toy gears.
Practise this questionQuestion
Question text
02 Figure 5 shows a young child using a baby walker.
Figure 5
02.1 The child is standing still.
What is the resultant vertical force on the child?
Give a reason for your answer.
[2 marks]
Resultant vertical force = N
Reason
Use the Physics Equations Sheet to answer questions 02.2 and 02.3.
02.2 Write down the equation which links distance (s), force (F) and work done (W).
[1 mark]
02.3 The child pushed the baby walker 2.8 m across a horizontal floor.
The work done by the child was 35 J.
Calculate the horizontal force the child applied to the baby walker.
[3 marks]
Horizontal force = N
02.4 The child pushed the baby walker from a carpet onto a hard floor.
The child applied the same horizontal force to the baby walker.
Explain why the speed of the baby walker increased.
[2 marks]
There are some toy gears on the front of the baby walker.
Figure 6 shows the gears.
Figure 6
The child applies a force to gear A.
This causes a moment about the pivot, so gear A rotates.
Use the Physics Equations Sheet to answer questions 02.5 and 02.6.
02.5 Write down the equation which links distance (d), force (F) and
moment of a force (M).
[1 mark]
02.6 The child applies a force of 2.0 N on gear A.
The perpendicular distance between the force and the pivot is 7.5 cm.
Calculate the moment of the force about the pivot.
[3 marks]
Moment of force = Nm
02.7 Explain what happens to gear B when the child applies the force to gear A.
[2 marks]
Mark scheme
Show the mark scheme
Question 2
AO /
Question Answers Extra information Mark
Spec. Ref.
02.1 0 (N) 1 AO2
4.5.6.2.1
the child isn’t accelerating MP2 dependent on MP1 1
(vertically)
or
upwards forces are equal to the allow forces are balanced
downwards forces
AO /
Spec. Ref.
02.2 work done = force × distance 1 AO1
4.5.2
or
W = F × s
AO /
Spec. Ref.
02.3 35 = F × 2.8 1 AO2
4.5.2
35 1
F =
2.8
F = 12.5 (N) allow 13 (N) 1
AO /
Spec. Ref.
02.4 the resistive force has allow friction (between the 1 AO3
decreased wheels and the floor) has 4.5.1.4
decreased 4.5.6.2.1
4.5.6.2.2
so the resultant force increases – – 1 –
AO /
Spec. Ref.
02.5 moment = force × distance 1 AO1
4.5.4
or
M = F × d 9
AO /
Spec. Ref.
02.6 7.5 cm = 0.075 m 1 AO2
4.5.4
M = 2.0 × 0.075 allow a correct substitution of an 1
incorrectly / not converted value
of d
M = 0.15 (Nm) allow an answer consistent with 1
an incorrectly / not converted
value of d
AO /
Spec. Ref.
02.7 gear B rotates in the opposite 1 AO2
direction (to gear A) 4.5.4
or
gear B rotates clockwise
or
gear B rotates faster than gear
A
(because) gear A exerts a force 1
on gear B
or
(because) gear A causes a
moment about the pivot of gear
B
Total Question 2 14
How to answer it
Forces, Work Done, and Moments Study Guide
What this question tests
This question assesses your understanding of forces, Newton's laws of motion, calculating work done, analyzing changing resistive forces, and applying the turning effect of forces (moments and gears). You will need to recall formulas, perform unit conversions, and structure physical explanations clearly.
Vertical Forces and Equilibrium
✅ Correct Answer
Resultant vertical force: 0 N
Reason: The child is not accelerating vertically / upwards forces are equal to downwards forces (balanced forces).
🧠 Exam Technique
Mark 2 is strictly dependent on Mark 1. If you write a non-zero force, the reason cannot score. Always link a resultant force of zero directly to constant velocity or stationary states (no acceleration).
Equation Linking Distance, Force, and Work Done
✅ Correct Answer
work done = force × distance (or W = F × s )
💡 Key Knowledge
You must memorise standard equations from the physics equations sheet. Word equations or accepted standard symbols are both marked correct.
Calculating Horizontal Force (Work Done)
📐 Step-by-Step Calculation
- State equation: W = F × s
- Substitute values: 35 = F × 2.8
- Rearrange & Solve: F = 35 / 2.8 = 12.5 N
❌ Common Errors
Students often multiply work done by distance instead of rearranging the formula. Always write out the formula with numbers before rearranging to secure working marks.
Explaining Speed Changes (Carpet to Hard Floor)
✅ Correct Answer
- The resistive force / friction has decreased.
- Therefore, the resultant force increases (causing acceleration).
💡 Key Knowledge
Carpet creates more friction than a smooth hard floor. Less friction means a larger net forward force, causing the object to accelerate (speed up).
Equation for Moment of a Force
✅ Correct Answer
moment = force × distance (or M = F × d )
💡 Key Knowledge
Distance must always be the perpendicular distance from the line of action of the force to the pivot.
Calculating the Moment of a Force
📐 Step-by-Step Calculation
- Convert units: 7.5 cm = 0.075 m
- Substitute formula: M = 2.0 × 0.075
- Calculate final answer: M = 0.15 Nm
❌ Common Errors
The unit trap! Forgetting to convert centimetres into metres is the #1 place students lose marks on moments calculations. Always check your unit prefixes (centi = divide by 100).
Behavior of Interlocking Gears
✅ Correct Answer
Gear B rotates in the opposite direction (clockwise) / rotates faster, because gear A exerts a force on gear B / causes a moment about the pivot.
💡 Key Knowledge
When two gears mesh, the smaller gear rotates faster than the larger gear, and adjacent gears always turn in opposite directions to one another.
Topics
Physics · P5: Forces
Question and mark scheme from the AQA GCSE Physics examination, Physics Paper 2 (Higher), June 2024. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.