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FeynmanFtw
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Thread moved from the technical forums to the schoolwork forums
TL;DR Summary: Solving a problem regarding a train going past a station using length contraction and the Lorentzian transformation.
I'll dive straight in. I encountered a problem where there is a train travelling at 0.6c going past a station, length 500 m when measured by an observer at rest relative to the station. The question asks what is the perceived length of the station relative to an observer on the train.
I simply used the length contraction formula:
$$L = \frac{L_0}{\gamma} = \frac{500}{1.25} = 400 \textnormal{ m}$$
In the answer, it uses the equation:
$$\Delta x' = \gamma(\Delta x - v\Delta t) = \frac{5}{4}\cdot 500 = 625 \textnormal{ m}$$
I'm pretty sure the first answer is correct, but I must admit I'm really confounded by the answer from the question. I haven't fully covered the Lorentzian transformation equations so I don't feel confident in tackling that part yet, so I would appreciate some help on this!
Could it be a mistake in the mark scheme (they do seldom happen, unfortunately).
I'll dive straight in. I encountered a problem where there is a train travelling at 0.6c going past a station, length 500 m when measured by an observer at rest relative to the station. The question asks what is the perceived length of the station relative to an observer on the train.
I simply used the length contraction formula:
$$L = \frac{L_0}{\gamma} = \frac{500}{1.25} = 400 \textnormal{ m}$$
In the answer, it uses the equation:
$$\Delta x' = \gamma(\Delta x - v\Delta t) = \frac{5}{4}\cdot 500 = 625 \textnormal{ m}$$
I'm pretty sure the first answer is correct, but I must admit I'm really confounded by the answer from the question. I haven't fully covered the Lorentzian transformation equations so I don't feel confident in tackling that part yet, so I would appreciate some help on this!
Could it be a mistake in the mark scheme (they do seldom happen, unfortunately).
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