Let’s solve each question step-by-step using the
Distance-Time Graph provided.
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📊 Understanding the Graph:
-
X-axis (horizontal) = Time (seconds)
-
Y-axis (vertical) = Distance (meters)
-
Point A: (0, 0) — Start
-
Point B: (10, 200) — After 10 seconds, car is at 200m
-
Point C: (30, 200) — From 10s to 30s, distance doesn’t change →
car is stopped
-
Point D: (60, 500) — At 60 seconds, car is at 500m
Slant lines (AB and CD) = car is moving
Flat line (BC) = car is stopped
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##
✔ Question 1: What is the speed of the car on its journey from C to D?
Speed = Distance ÷ Time
From C to D:
- Distance traveled = 500m – 200m =
300m
- Time taken = 60s – 30s =
30s
→ Speed = 300m / 30s =
10 m/s
✔ Answer: 10 m/s
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##
✔ Question 2: On which part of the journey did the car travel faster?
Compare speeds of AB and CD segments.
Segment AB (0 to 10s):
- Distance = 200m – 0m = 200m
- Time = 10s
- Speed = 200m / 10s =
20 m/s
Segment CD (30 to 60s):
- As calculated above:
10 m/s
→
AB is faster than CD
✔ Answer: From A to B
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##
✔ Question 3: Calculate the speed of the car during the first 10 seconds!
That’s segment AB — already calculated above.
→ Speed = 200m / 10s =
20 m/s
✔ Answer: 20 m/s
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##
✔ Question 4: For how long did the car stop?
Car stops during segment BC (flat line).
- Starts at 10s, ends at 30s
→ Duration = 30s – 10s =
20 seconds
✔ Answer: 20 seconds
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##
✔ Question 5: What is the average speed of the car for the whole journey?
Average speed = Total distance ÷ Total time
- Total distance = 500m (from A to D)
- Total time = 60s
→ Average speed = 500m / 60s ≈
8.33 m/s
✔ Answer: 8.33 m/s (or 25/3 m/s if you prefer fraction)
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##
✔ Question 6: What is the average speed of the car for the time it was moving?
This means we
exclude the stopped time (BC segment).
Total moving time = Time AB + Time CD = 10s + 30s =
40s
Total distance moved = 500m (same as before)
→ Average speed while moving = 500m / 40s =
12.5 m/s
✔ Answer: 12.5 m/s
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## 🧾 Final Answers Summary:
1.
10 m/s
2.
From A to B
3.
20 m/s
4.
20 seconds
5.
8.33 m/s
6.
12.5 m/s
Let me know if you’d like a visual explanation or graph annotations!
Parent Tip: Review the logic above to help your child master the concept of speed graph worksheet.
