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Q1.16: NCERT Physics - Part 1 UNITS AND MEASUREMENT 1.16 Solution: Explain this common observation clearly: If you look out of the …
⚠️ Common Exam Traps & Conceptual Pitfalls
Students often incorrectly assume that distant objects appear stationary because their linear velocity is zero, rather than recognizing that their apparent motion is governed by angular velocity $\omega = v/r$. The key insight is that as the distance $r$ increases, the angular displacement per unit time decreases, making distant objects appear static relative to the observer.
Explain this common observation clearly: If you look out of the window of a fast moving train, the nearby trees, houses etc. seem to move rapidly in a direction opposite to the train's motion, but the distant objects (hill tops, the Moon, the stars etc.) seem to be stationary.
Step-by-Step Verified Solution
**Answer:** The angular change per second is the key.
**Step-by-Step Explanation:**
When the train moves, the angular displacement of nearby objects (trees, houses) is large per unit time, so they appear to move rapidly backward.
For distant objects, the angular displacement per unit time is very small (since angular speed and is very large), so they appear practically stationary.
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