Question 1
Multiple choiceEasy1 markA train moves at constant velocity to the right relative to a platform. Light flashes are emitted from its front and rear, and a passenger at the train’s midpoint receives them simultaneously. Which row gives the emission times of the flashes in the train and platform frames?
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Answer: A. The passenger is equally distant from both ends in the train frame, so simultaneous arrival means the emissions were simultaneous in that frame. Relativity of simultaneity means they are not simultaneous in the platform frame; for a train moving right, the front emission is later.
B: reverses the event order in the platform frame; the front emission is later, not the rear one.
C: treats simultaneity as unchanged between frames and assigns the front event an earlier time in the train frame.
D: also assigns simultaneity to the platform frame, and reverses the front–rear order in the train frame.
Remember: events simultaneous in one inertial frame need not be simultaneous in another.