When at rest, the Sigma- particle has a lifetime of 0.15 ns before it decays into a neutron and a pion. One particular Sigma- particle is observed to travel 3.2 cm in the lab before decaying.
What was its speed? (Hint: Its speed was not 2/3 c)
The Attempt at a Solution
Since it wants the answer in terms of the speed of light c,
2.1333*10^8 / 3*10^8 = .7111c
This isn't the right answer though, help please :)
EDIT: I just realized that v=x/t^2, but that gives me an implausible answer of 4740740741c, so I still need help