(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Two spaceships (A and B) are travelling in opposite ways. An observer in Earth measures both velocities.

The speed of ship A (Va) = 0.75c.

The speed of ship B (Vb) = 0.85c.

What's the speed of **** B regarding ship A?

2. Relevant equations

3. The attempt at a solution

At first I tried solving it using Galileu's relativity, but I've reached the result of 1.6c.

Then I remembered that when we're dealing with speeds close to c we have to use Einstein's special relativity, so I've looked around all the formulas I have but none of them involved velocity, only time, spaceship length, and there are also the ones involving energy but I don't think that has nothing to do with this exercise.

Thanks!

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# Homework Help: Special relativity problem

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