To analyze the scenario, let’s clarify the movements of the two people on the train.
- The train is moving north at a speed of 10 m/s.
- Each person is walking inside the train at a speed of 1 m/s relative to the train.
Now, let's determine their speed relative to the ground:
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If the people are walking in the same direction as the train (north), we add their speed to the train's speed:
\[ \text{Speed relative to ground} = \text{Train speed} + \text{Walking speed} = 10 \text{ m/s} + 1 \text{ m/s} = 11 \text{ m/s (North)} \]
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If the people are walking in the opposite direction (south), we subtract their speed from the train's speed:
\[ \text{Speed relative to ground} = \text{Train speed} - \text{Walking speed} = 10 \text{ m/s} - 1 \text{ m/s} = 9 \text{ m/s (North)} \]
In your statement, you mentioned that their motion is 9 m/s North. This would imply that they are walking in the opposite direction of the train's motion (south).
To summarize:
- Walking north (same direction as the train): 11 m/s North relative to the ground.
- Walking south (opposite direction to the train): 9 m/s North relative to the ground.
Please let me know if you need further clarification!