5. In the laboratory, it travels a distance d = 0.00105 m = vt, where v = 0.992c and t is the time measured
on the laboratory clocks. We can use Eq. 38-7 to relate t to the proper lifetime of the particle t
0
:
t =
t
0
1
− (v/c)
2
=
⇒ t
0
= t
1
−
v
c
2
=
d
0.992c
1
− 0.992
2
which yields t
0
= 4.46
× 10
−13
s.