5. A spaceship passes you at the speed of 0.90c. You measure its length to be 50.0 m. What is its length when at rest? 6. You are a space traveller, moving at 0.60c with respect to Earth, on your way to a star that is stationary relative to Earth. You measure the length of your trajectory to be 8.0 light-years (ly). Your friend makes the same journey at 0.80c with respect to Earth. What does your friend measure the length of the trajectory to be? 7. A spacecraft travels along a space station platform at 0.65c relative to the platform. An astronaut on the spacecraft determines the platform to be 3.00 X 102 m long. What is the length of the platform as measured by an observer on the platform