A rod flies with constant velocity past a mark which is stationary in the reference frame K In the frame K it takes t 20 ns for the rod to fly past the mark In the reference frame fixed to the rod the mark moves past the rod for t ' 25 ns Find the proper length of the rod ...

In the frame K the length of the rod is related to ...

A rod flies with constant velocity past a mark which is stationary in the reference frame K.

Question:

A rod flies with constant velocity past a mark which is stationary in the reference frame K. In the frame K it takes Δt = 20 ns for the rod to fly past the mark. In the reference frame fixed to the rod the mark moves past the rod for Δt' = 25 ns. Find the proper length of the rod.