Answer:
So length of the tube in electron reference frame is 0.7348 m
Step-by-step explanation:
We have given total length of the tube

Velocity of electron v = 0.99999997c ,here c is the velocity of light
We have to find the length of the tube in electron reference frame
Length of the tube in electron reference frame is given by

So length of the tube in electron reference frame is 0.7348 m