Walkway speed: 0.5 m/s
Everything is relative to the walkway unless stated otherwise.
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Carla’s movement breakdown:
1. First phase:
• She runs at 1 m/s relative to walkway, so total speed = 1 + 0.5 = 1.5 m/s
• Time = 40 seconds
• Distance covered = 1.5 \times 40 = 60 meters
2. Second phase:
• She stops running and stands still.
• So she is only moved by the walkway = 0.5 m/s
• Time = x seconds
• Distance covered = 0.5 \times x meters
3. Third phase:
• She resumes running at 1.5 m/s relative to walkway, so total speed = 1.5 + 0.5 = 2 m/s
• Time = 5 seconds
• Distance covered = 2 \times 5 = 10 meters
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Total walkway length: 200 meters
So total distance Carla covers is 200 m.
From her 3 phases:
\text{Total distance} = 60 + 0.5x + 10 = 200
70 + 0.5x = 200
\Rightarrow 0.5x = 130
\Rightarrow x = 260
✅ So, x = 260 seconds
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Daniel’s speed:
• Walks at 0.5 m/s relative to walkway
• Walkway is moving at 0.5 m/s
• So total speed = 0.5 + 0.5 = 1 m/s
• Walkway length = 200 m
• Time = 200 / 1 = 200 seconds
✅ So, y = 200 seconds
And E , C