Thread: Special relativity - time dilation

Unbelievably high energy particles, called cosmic rays, are continuously bombarding our atmosphere and producing unstable particle particles known as muons. The image below shows one such muon detected by the ATLAS particle physics detector at the LHC. The average lifetime for a muon, at rest, is 2.2 µs. If the muons from cosmic rays are produced travelling at 0.99956c (c=speed of light in vacuum) how long do they live, on average, before decaying?

[Specify units of 's', 'ms' or 'us' (µs) in your answer.]



I based this question off of the time dilation


and since they are saying its at rest
would I assume that v^2/c^2 is zero?
and simply the equation is 2.2 micro seconds/ 1?