"An electron moves to the right with a speed of 0.90c relative(adsbygoogle = window.adsbygoogle || []).push({});

to the laboratory frame. A proton moves to the right

with a speed of 0.70c relative to the electron. Find the

speed of the proton relative to the laboratory frame."

u' = (u-v)/(1-(uv/c_{2})) where u will be velocity of electron with respect to lab frame, v is velocity of proton with respect to lab frame and u' is their relative velocity. ie, u=0.9c, u'=0.7c

Solving for v yields 0.54c. But my solutions book says 0.98c? Im pretty sure they are wrong...it would be 0.98c if the proton were moving to the left with respect to electron...am i right?

1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

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# Homework Help: Basic special relativity addition of velocities problem

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