Lorentz transformation (cf. probs. 1.6.19+21 in textbook) an observer standing on earth observes spaceship travel (a) two spaceships are heading in the same direction toward earth, one at vi-0.95c and the other one at v2-0.85c relative to earth. what is the speed of spaceship- 1 as seen from the captain in spaceship-2? (b) two other spaceships are heading toward earth from opposite directions, at speeds of vz-0.8c and va-0.9c relative to earth. what is the speed of spaceship- 4 as seen from the captain in spaceship-3? (c) if spaceship-1 is 0.3ly (1 ly-1 lightyear, the distance light travels in one year) away from earth, how much older (in seconds) will be: (i) the observer, and (ii) the captain, once the spaceship has landed on earth?