Imagine that a relativistic train travels past your lecture room at a speed of 0
ID: 1504522 • Letter: I
Question
Imagine that a relativistic train travels past your lecture room at a speed of 0.873 c. The passengers of the train claim that when they measure the length of the train using standard meter bars found on the train, the length comes out to be 72.2 m. What would be the length of the train in the frame of the lecture room if you measured it? (in m)
How long would a regular 50 minute long class in the lecture room last for the passengers of the train if they measured it while sitting on the train? (in min)
Explanation / Answer
given data
v=0.873c
Lo = 72.2 m
What would be the length of the train in the frame of the lecture room if you measured it? (in m)
from relativity L = Lo*sqrt(1-(v/c)^2)
L = 72.2*sqrt(1-0.873^2) =35.21m
How long would a regular 50 minute long class in the lecture room last for the passengers of the train if they measured it while sitting on the train?
t' = t/sqrt(1-(v/c)^2)
t' = 50/sqrt(1-0.873^2) = 102.5 min