Worksheet on interpreting distance-time graphs to calculate speed and analyze motion.

Let's solve each question step by step using the distance-time graph provided.

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Understanding the Graph:

- The x-axis represents time in seconds.
- The y-axis represents distance in meters.
- The car moves from point A to D, covering a total distance of 500 meters.
- The graph has three segments:
- AB: From (0,0) to (10,200) — moving
- BC: From (10,200) to (30,200) — flat line → stopped
- CD: From (30,200) to (60,500) — moving again

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Question 1: What is the speed of the car on its journey from C to D?

We calculate speed using:

> Speed = Distance / Time

From C to D:
- Distance = 500 m – 200 m = 300 m
- Time = 60 s – 30 s = 30 s

So,

> Speed = 300 m / 30 s = 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 in AB and CD.

#### Segment AB:
- Distance = 200 m – 0 m = 200 m
- Time = 10 s – 0 s = 10 s
- Speed = 200 / 10 = 20 m/s

#### Segment CD:
- As calculated above: 10 m/s

So, the car traveled faster during AB.

✔ Answer: AB

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Question 3: Calculate the speed of the car during the first 10 seconds.

This is the same as segment AB.

- Distance = 200 m
- Time = 10 s
- Speed = 200 / 10 = 20 m/s

✔ Answer: 20 m/s

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Question 4: For how long did the car stop?

The car stops when the graph is flat (BC).

- BC goes from t = 10 s to t = 30 s
- Duration = 30 – 10 = 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 = 500 m
- Total time = 60 s

> Average speed = 500 / 60 ≈ 8.33 m/s

✔ Answer: 8.33 m/s (or 25/3 m/s)

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Question 6: What is the average speed of the car for the time it was moving?

Now we only consider the moving parts, not the stop.

- Moving time:
- AB: 10 s
- CD: 30 s
- Total moving time = 10 + 30 = 40 s
- Total distance moved = 500 m

> Average speed = 500 m / 40 s = 12.5 m/s

✔ Answer: 12.5 m/s

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✔ Final Answers:

1. 10 m/s
2. AB
3. 20 m/s
4. 20 seconds
5. 8.33 m/s
6. 12.5 m/s

Let me know if you'd like this explained with diagrams or formulas!