A particle known as a pion lives for a short time before breaking apart into other particles. Suppose a pion is moving at a speed of 0.986c, and an observer who is stationary in a laboratory measures the pion's lifetime to be 3.4 × 10-8 s. (a) What is the lifetime according to a hypothetical person who is riding along with the pion? (b) According to this hypothetical person, how far does the laboratory move before the pion breaks apart?

Respuesta :

Answer: (a) t = 20.36.[tex]10^{-8}[/tex]s

(b) d = 60.225 m

Explanation: According to the Special Relativity Theory proposed by Albert Einstein, the laws of physics are the same for all non-accelerating observers and speed of light is the same in vaccum, no matter the speed the pbserver is travelling. with these statements, Einstein realized that space and time interwoven in a continuum called space-time, i.e., events that occur for one observer at the same time, occurs at different times for a second observer.

(a) To determine the lifetime and since the person is riding along:

t = [tex]\frac{t_{0} }{\sqrt{\frac{1-v^{2} }{c^{2} } } }[/tex] , in which:

t is time observed in the other time frame

t₀ is time in the observer's own reference

v is velocity of the object

c is the speed of light in vacuum (c=3.[tex]10^{8}[/tex]m/s)

Calculating:

t = [tex]\frac{3.4.10^{-8} }{\sqrt{\frac{1 - 0.986c^{2} }{c^{2} } } }[/tex]

t = [tex]\frac{3.4.10^{-8} }{\sqrt{0.028} }[/tex]

t = 20.36.[tex]10^{-8}[/tex]

The lifetime, according to the hypothetical person is 20.36.[tex]10^{-8}[/tex] seconds.

(b) The pion is moving at a speed of v = 0.986c. In 20.36 seconds,

the laboratory moves:

v=[tex]\frac{d}{t}[/tex]

d = v.t

d = 0.986.3.[tex]10^{8}[/tex].20.36.[tex]10^{-8}[/tex]

d = 60.225

The lab moved 60.225 meters.