23. K ´rests rod proper length l0 which is 1 m. The rod is arranged so that makes an angle φ0 = 45 ° with the axis x. The length l of the rod and the angle φ in the system K, if the speed of υ0 K ´relative to K c is equal to 0.8.
Detailed solution. Decorated in Microsoft Word 2003. (Target decided to use formula editor)