1. The problem statement, all variables and given/known data Sally and Sheldon have identical meter sticks. Sally is on earth, and sheldon is in a spacecraft that moves at 0.5c relative to sally. Sheldon leaves the spaceship at 0.1c relative to the spacecraft in a launch pad, moving away from sally. according to sally, what is the length of sheldon's meter stick? 2. Relevant equations x=gamma*(x-vt) 3. The attempt at a solution if in sheldon's frame: Lo = 1m = length of meter stick In sally's frame: L=gamma*(x'-vt'-x-vt) but t1=t2 so L=Lo/gamma L= 0.8 m So Sally sees sheldon's meter stick as 0.8 m long.