Questions
Question 1
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What is proper length?
Question 2
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State the length contraction formula.
Question 3
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Which length is larger, \(L_0\) or \(L\), for a moving object?
Question 4
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A rod has proper length \(10.0\,\mathrm m\) and moves with \(\gamma=2.00\). Find its measured moving length.
Question 5
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A rod moves at \(0.600c\). Find \(\gamma\).
Question 6
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A spacecraft has proper length \(100\,\mathrm m\) and moves at \(0.800c\). What length does Earth measure?
Question 7
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A moving object is measured to be \(4.00\,\mathrm m\) long. If \(\gamma=1.25\), find its proper length.
Question 8
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Why must the two endpoints of a moving object be measured simultaneously in the observer's frame?
Question 9
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A rod has proper length \(6.00\,\mathrm m\) and is measured as \(3.60\,\mathrm m\). Find \(\gamma\) and the speed.
Question 10
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A meter stick moves at \(0.900c\) parallel to its length. Find its length in the lab.
Question 11
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A square plate moves parallel to one of its sides at \(0.800c\). Its proper side length is \(2.00\,\mathrm m\). What are the measured side lengths in the lab?
Question 12
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A tunnel has proper length \(500\,\mathrm m\). A train moving at \(0.600c\) passes through it. What tunnel length is measured in the train frame?
Question 13
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At what speed is a moving object's measured length half its proper length?
Question 14
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A rod is angled so it has a \(3.00\,\mathrm m\) component parallel to motion and a \(4.00\,\mathrm m\) transverse component in its rest frame. If \(\gamma=2.00\), find its measured length.
Question 15
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Explain why length contraction and time dilation are linked by simultaneity.
Question 16
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Derive length contraction using endpoint events simultaneous in the lab frame.
Question 17
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A student says the moving object physically gets crushed. Correct this interpretation.
Question 18
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Show that no length contraction occurs for dimensions perpendicular to the relative velocity.
Question 19
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A rod has proper length \(L_0\). Find the fractional contraction \((L_0-L)/L_0\) in terms of \(\gamma\).
Question 20
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Show that length contraction disappears in the Newtonian limit.