A particle is observed to be created at t = 100ns , travel with speed Ux = -c/3 and then decay at t = 300ns. To an observer who was moving at speed of -3/5 c along the common x - x' axis:(adsbygoogle = window.adsbygoogle || []).push({});

A) waht was the velocity of the particle during its trip?

Ux' = Ux - V / 1 - VUx/c^2

however this time they are moving in the same direction so the numerator and denominator becomes plus signs and i get 13/18 c

B) what distance between the position where the particle was created and the position at which it decayed?

Ok since moving clocks move slower, the observer moving will see the 200ns actually take 200 times gamma = 250ns to complete

Since D = Vt = 13c / 18 times 250ns

C) How much time elapsed between the instant it was creaed and the instant it decayed?

I think i answered it in B = 250ns

D) How can it be that the observers in two different frames namely S and S' get the same answers for parts b and c? Desnt this contradict relaitivity? (i.e. what happened to length contraction and time dilation?)

I don't understand what frame is S and S' here but I would think since in either frame the observer thinks that his frame is at rest but the world moves past him in one direction or the other. So at relative speed lenght contraction and tiem dilation occur for both sides - an observer would se time somehwhere else move slower, while the observer from somewhere else would see the original observer's time move slower too.

pease tell me if i am correct in what i have done so far...

your assitance is greatly appreciated

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# Homework Help: What if a particle travelled at c/3

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