Solved: The proper length of one spaceship is three times
Chapter 26, Problem 26.29(choose chapter or problem)
The proper length of one spaceship is three times that of another. The two spaceships are traveling in the same direction and, while both are passing overhead, an Earth observer measures the two spaceships to have the same length. If the slower spaceship has a speed of 0.350c with respect to Earth, determine the speed of the faster spaceship.
Unfortunately, we don't have that question answered yet. But you can get it answered in just 5 hours by Logging in or Becoming a subscriber.
Becoming a subscriber
Or look for another answer