AQA GCSE Combined Science: Trilogy Physics Paper 2 (Higher), June 2025: Question 1
9 marks · Low Demand difficulty · Short Answer
Calculate speed and resultant force, interpret a distance-time graph, and identify Newton's laws for a dog sled.
Practise this questionQuestion
Question text
01 In a dog-sled race, a team of dogs pull on a rope attached to a sled.
Figure 1 shows a dog-sled team.
Figure 1
Use the Physics Equations Sheet to answer questions 01.1 and 01.2.
01.1 What equation links distance travelled, speed and time?
[1 mark]
Tick ( ) one box.
distance travelled = speed × time
speed = time × distance travelled
time = distance travelled × speed 3
01.2 The longest dog-sled race in the world covers a distance of 1 500 000 m.
One team finished the race in a time of 670 000 s.
Calculate the average speed of this team during the race.
[3 marks]
Average speed = m/s
01.3 At the start of the race, 6 dogs pulled on the rope.
The average forward force on the sled from each dog was 370 N.
The backwards force on the sled from friction was 520 N.
Calculate the resultant force on the sled.
[2 marks]
Resultant force = N
Figure 2 shows a distance–time graph for the sled at the start of the race.
Figure 2
01.4 What does the gradient of the graph in Figure 2 represent?
[1 mark]
01.5 Later in the race, the sled moved at a constant speed along a flat, horizontal path.
What was the relationship between the size of the horizontal forces acting when the
sled moved at a constant speed?
[1 mark]
Tick ( ) one box.
friction + air resistance < pull of the rope on the sled
friction + air resistance = pull of the rope on the sled
friction + air resistance > pull of the rope on the sled
0 1*046*
. The rope exerted a force on the sled when the sled was moving.
What is the Newton’s Third Law pair to the force of the rope on the sled?
[1 mark]
Tick ( ) one box.
The force of friction on the sled
The force of the dogs on the rope
The force of the sled on the rope
Mark scheme
Show the mark scheme
Question 1
AO /
Question Answers Extra information Mark
Spec. Ref.
01.1 distance travelled = speed × time 1 AO1
6.5.4.1.2
AO /
Spec. Ref.
01.2 1 500 000 = v × 670 000 1 AO2
6.5.4.1.2
1 500 000 1
v =
670 000
V = 2.2… (m/s) 1
AO /
Spec. Ref.
01.3 F = (6 × 370) - 520 1 AO2
6.5.1.4
F = 1700 (N) 1
if no other mark awarded allow
1 mark for 370 - 520 = (-)150 (N)
AO /
Spec. Ref.
01.4 speed allow velocity 1 AO1
6.5.4.1.4
AO /
Spec. Ref.
01.5 friction + air resistance = pull of the rope on the sled 1 AO1
6.5.1.4
6.5.4.2.1
AO /
Spec. Ref.
01.6 the force of the sled on the rope 1 AO1
6.5.4.2.3
Total Question 1 9
How to answer it
Forces, Speed, and Motion: Dog-Sled Analysis
What this question tests
This question assesses foundational Physics concepts: recalling and rearranging the speed equation, calculating resultant forces involving multiple objects, interpreting distance–time graphs, and applying Newton’s First and Third Laws of Motion to real-world contexts.
Speed, Distance, and Time Equation
AQA Specification Reference: 6.5.4.1.2
✅ Correct Answer
Tick box 1: distance travelled = speed × time
🧠 Exam Technique
This is given directly on the Physics equation sheet as:
s = v t
Always double-check your formula sheet before guessing.
Calculating Average Speed
AQA Specification Reference: 6.5.4.1.2
📐 Step-by-Step Calculation
- Substitute into formula:
1 500 000 = v × 670 000 [1 mark] - Rearrange for speed (v):
v = 1 500 000 / 670 000 [1 mark] - Calculate final answer:
v = 2.2388... ≈ 2.2 m/s [1 mark]
❌ Common Calculation Errors
- Inverting division: Dividing time by distance ( 670 000 / 1 500 000 = 0.45 ). Speed is distance divided by time.
- Miscounting zeros: When typing large numbers into a calculator, double-check zero counts (5 zeros in 1.5 million, 4 zeros in 670 thousand).
Resultant Force with Multiple Dogs
AQA Specification Reference: 6.5.1.4
📐 Step-by-Step Calculation
- Calculate total forward force:
6 dogs × 370 N each = 2220 N - Subtract backward resistive force:
Resultant Force = 2220 N - 520 N [1 mark] - Final Result:
1700 N [1 mark]
❌ Common Traps
- Missing the word "each": Students frequently compute 370 - 520 = -150 N , forgetting there are 6 dogs. (Awarded 1 compensation mark only).
- Adding instead of subtracting: Friction opposes forward motion, so it must be subtracted.
Interpreting a Distance–Time Graph
AQA Specification Reference: 6.5.4.1.4
✅ Correct Answer
speed (or velocity)
💡 Key Knowledge
Gradient = change in y / change in x
On this graph, that equals distance / time , which defines speed.
Note: The curve steepens between 0 and 6 seconds, showing the sled is accelerating.
Newton's First Law (Constant Speed)
AQA Specification Reference: 6.5.1.4 & 6.5.4.2.1
✅ Correct Answer
Tick box 2:
friction + air resistance = pull of the rope on the sled
💡 Newton's First Law
If an object moves at a constant speed in a straight line, the resultant force must be zero.
Therefore, total forward force = total backward forces.
❌ Common Misconception
Many students believe forward force must be greater than backward force to keep moving. A greater forward force causes acceleration, not constant speed!
Newton's Third Law Pairs
AQA Specification Reference: 6.5.4.2.3
✅ Correct Answer
Tick box 3:
The force of the sled on the rope
🧠 The "Swap the Nouns" Rule
Newton's Third Law states: If object A exerts a force on object B, then object B exerts an equal and opposite force on object A.
Original: Force of rope on sled.
Third Law Pair: Force of sled on rope.
Topics
Physics · P5: Forces
Question and mark scheme from the AQA GCSE Combined Science: Trilogy examination, Physics Paper 2 (Higher), June 2025. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.