A burst of mesons travel down an evacuated beam tube at Fermilab at beta =.92 with respect to the laboratory.
a) compute y for this group of pions.
b) The proper mean lifetime of pions is 2.6*10^-8 sec. What mean lifetime is measured in the lab?
c) If the burst contained 50,000 pions, how many remain after the group has traveled 50 meters down the beam tube? d) what would be the answer to c) ignoring time dilation?