How Fast is the Alien Spacecraft Flying Overhead?

da_warped_1
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hey i just need a lil help with this question

An alien spacecraft is flying overhead at a great distance as you stand in your backyard. Yyou see a bright signal light in the spaceship blink on for 190.0 ms. The commander of the spacecraft measures that the signal is on for 12.0 ms.

what is the speed of the spacecraft relative to the earth?

i calculated the speed and it comes out to be greater than the speed of light, which is impossible. just wondering if i had calculated it wrong or maybe someone has a better explanation!

thanks
 
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Show your work and someone will probably be able to tell you where you went wrong. Otherwise we can only guess!
 
i worked it out, just a simple miscalculation.

cheers
 
you should get ...

v=0.998c​

So that's a fast vessel.

pess
 

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