Question

A large number of very industrious people make a very long pole. It is 10.0 light years long! ( As they measure it. ) Soon a spaceship flies along the length of the pole at 90% the speed of light. How much time passes on the spaceship from the moment the ship passes the first end of the pole to the moment the ship passes the second end of the pole

Answer 1

L = L0 ( 1 - v^2/c^2))1/2 where L0 is the proper length

L = 10 L-y (1 - .9^2)^1/2 = 4.36 L-y length of pole measured by ship

t = 4.36 L-y / .9 c = 4.84 y since the ship travels at .9 c