An observer on Earth sees an alien vessel
esl wh;sbn2b5j0j.. :4r 6wyk j mf9ea approach at a speed of 0.60c. The Enterprise comes to the rescue (Fig. Below), overtaking the aliens while moving directly toward Earth at a spe
2yj .j.9srebbhk s:6wa5em;lnw f0j 4ed of 0.90c relative to Earth. What is the relative speed of one vessel as seen by the other? u =
c