Observer A sees a ruler moving by in a relativistic train and measures its length to be L_A. Observer B moves together with the train and measures the length of the ruler to be L_B. These two results will be such that A) L_A L_B. B) L_A = L_B. C) L_A

Question

Observer A sees a ruler moving by in a relativistic train and measures its length to be L_A. Observer B moves together with the train and measures the length of the ruler to be L_B. These two results will be such that A) L_A > L_B. B) L_A = L_B. C) L_A < L_B. D) L_A could be greater or smaller than L_B depending on the direction of the motion.

Quizplus · Accepted Answer

According to the theory of special relativity, length contraction occurs when an object moves relative to an observer. The length contraction factor is given by γ = 1/√(1- v^2/c^2), where v is the relative velocity between the observer and the object, and c is the speed of light. As observer A sees the ruler moving, the ruler appears shorter to observer A than to observer B who is moving with the ruler. Therefore, L_A < L_B.

Observer a Sees a Ruler Moving by in a Relativistic