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visharad
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Homework Statement
a) What is the speed of proton that has relativistic γ factor of 10^10? Write as (1-ε)c
b) A proton with γ=10^10 is chased by a photon across a galaxy. Observer A at one end of the galaxy (xA=0) sees the proton at t1=0 and the photon at t2 = 1.33 x 10^-8 s. According to A, how far apart are the two particles at t1?
c) Another observer B is at another end of the galaxy (xB=10^21 m). The two observers are at rest relative to each other. At what times will B see the particles go past?
d) How many years does it take the proton to cross the galaxy according to A and B?
Homework Equations
L = Lo [itex]\sqrt{1 - v^2/c^2}[/itex]
Δt = Δto/[itex]\sqrt{1 - v^2/c^2}[/itex]
The Attempt at a Solution
a) Y = 1/[itex]\sqrt{1 - v^2/c^2}[/itex]
1 - v^2/c^2 = 1/Y^2
v^2/c^2 = 1 - 1/Y^2
v^2/c^2 = 1 - 1/(10^10)^2
v^2/c^2 = 1- 1/10^20
v/c = sqrt(1 - 1/10^20)
v/c = (1 - 5 * 10^-21)
v = (1 - 5*10^-21) c
Is this correct?
b) The photon covers the distance in t2 - t1 = 1.33 x 10^-8 s
The distance = c t^2
= 3 x 10^8 x 1.33 x 10^-8
= 3.99 m
Is this correct?
c) Can we say that the observer B will see the proton pass by at t3 = t1 + xB/v and the photon pass by at t4 = t2 + xB/c ?
If not, then what is the correct method?
d) Can we simply divide distance (which is 10^21 m) by speed and convert into years? If not, then what is the correct method?
For c and d, I am not sure if we need to use Lorenz transformation equations. The observers are at rest relative to each other. So I think we do not need.