A rod of length l1 is at rest in frame K1. A rod of length l2 is at rest in frame K2. System K2 moves relative to system K1 at a speed of 0.7 s. The rods are oriented in the direction of motion of the K2 system. The length of the second rod in the K1 system is equal to the length of the first rod: l2’=l1. Which rod is longer in the K2 system and by how many times?

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