1-20. Use the binomial expansion to derive the following results for values of and use
when applicable in the problems that follow.
(a)
(b)
(c)
1-21. How great must the relative speed of two observers be for their time-interval measurements
to differ by 1 percent (see Problem 1-20)?
1-24. The proper mean lifetime of mesons (pions) is 2.6 _ 10–8 s. If a beam of such particles
has speed 0.9c, (a) What would their mean life be as measured in the laboratory? (b) How
far would they travel (on the average) before they decay? (c) What would your answer be to part
(b) if you neglected time dilation?