A spacecraft with circular (north and south sides - you are looking at the circular face) of diameter 325.0 m passes Earth moving eastward (in relation to you), at the speed of an electron whose kinetic energy is eleven times its rest energy.
(a) Determine the speed of the spacecraft in units of c, the speed of light in vaccuum.
(b) What are the dimensions of the ciruclar faces according to the earthbound observer?
(c) According to this earth bound observer, what is lifetimes of a copper-64 nucleaus on the captain's worktable, in the spacecraft if a copper-64 nucleus at rest has a lifetime of 12.7 h?