Astronaut Rob leaves Earth in a spaceship at a speed of 0.960c ...

[soccerdreamer_17]

Astronaut Rob leaves Earth in a spaceship at a speed of 0.960c relative to an observer on Earth. Rob's destination is a star system 14.4 light-years away (one light-year is the distance light travels in one year).
 
  Relative to a frame of reference that is fixed with respect to Earth, how long does it take Rob to complete the trip? A) 14.4 years
  B) 15.0 years
  C) 10.8 years
  D) 4.20 years
  E) 22.7 years

Question 2

The closest known star to our solar system is Alpha Centauri, which is approximately 4.30 light years away. A spaceship with a constant speed of 0.800c relative to the earth travels from Earth to this star.
 
  (a) How much time would elapse during the trip on a clock on board the spaceship? (b) How much time would elapse during the trip on a clock on Earth?

[stillxalice]

Answer to Question 1

B

Answer to Question 2

(a) 3.23 y (b) 5.38 y