A Pion Is an Unstable Particle That Has a Mean $2.55 \times 10 ^ { - 8 } \mathrm {~s}$

Multiple Choice

A pion is an unstable particle that has a mean lifetime of $2.55 \times 10 ^ { - 8 } \mathrm {~s}$ . This is the time interval between its creation in a nuclear process and its extinction into decay products, as measured in a frame of reference at rest with respect to the pion. An average pion is traveling at $0.230 \mathrm { c }$ relative to Earth. How far does it travel in its lifetime, relative to Earth?

A) $3.50 \mathrm {~m}$
B) $1.81 \mathrm {~m}$
C) $3.22 \mathrm {~m}$
D) $2.07 \mathrm {~m}$
E) $2.23 \mathrm {~m}$