A spacecraft with proper length 200 m travels at speed of 0.2c relative to an inertial frame of reference S. A small ball rolls inside the spacecraft with a velocity u'= 0.14c in the positive x direction relative to the spacecraft. ) a. What is the ball's speed as measured by an observer in frame s? Give answer in units of c. 0.330 b. How much time will it take to the ball to cross the whole spacecraft (end to end) according to an observer in frame S? Give answer in microseconds (1 s = 10-6 s). c. What is the distance the ball rolled (relative to frame S). Give answer in km.