QCEVault

Special relativity — Question 235

Original QCE Vault practice · 5 marks

Q235 · Practice questionComplex unfamiliar5 marks

QUESTION 235 (5 marks)

A straight rod has proper length 4.00 m4.00\,\mathrm m and makes an angle of 30.0∘30.0^\circ to the horizontal in its rest frame. The rod moves horizontally at 0.600c0.600c relative to a laboratory. The laboratory measures both endpoints simultaneously in the laboratory frame. Only the horizontal separation contracts.
Two schematic panels show the rod in its rest frame and in the laboratory. Each has horizontal and vertical axes. The rest-frame rod is labelled L0=4.00 m and 30.0 degrees; the laboratory rod has an unknown angle theta. A rightward motion arrow indicates v=0.600c. Not to scale.
a)
Determine the horizontal and vertical endpoint separations in the laboratory.
[2 marks]
b)
Determine the laboratory length of the rod and its angle to the horizontal.
[3 marks]
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