Consider a situation where we want to combine spacetime diagrams of Alice and Bob, where Bob is moving at a speed of 0.4c to the right (positive x direction). If we draw Alice’s xA axis as horizontal and tA axis as vertical, answer the following questions.(adsbygoogle = window.adsbygoogle || []).push({});

What is the equation, written in terms of xA and tA, that describes Bob’s tB axis (the world line where xB = 0) on Alice’s diagram?

My options are the following:

1. tA = γ xA/(0.4c), where γ is the Lorentz factor

2. tA = xA/(0.4c)

3. tA = (0.4c)(xA)

4. tA = γ (0.4c)(xA), where γ is the Lorentz factor

Can someone explain, step by step, how to derive the correct equation?

p.s. this is not homework, it`s just something for fun I found online that I want to understand...

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# Help with time-space diagram equations.

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