Answer to Question #98255 in Mechanics | Relativity for AbdulRehman

Question

Suppose that we a have tunnel of length 100m (measured in its rest frame)
and a train whose length is 100m (measured in its rest frame). The train
is moving along the track at .8c, and the robbers want to trap it using the
following scheme: one robber will sit at the entrance to the tunnel and
blow it up just after the back end of the train has entered, while the other
robber will sit at the exit of the tunnel and blow it up just before the front
end of the train gets there.
i) Draw a spacetime diagram of all of this in the (inertial) reference frame
of the tunnel. Be sure to include the explosions and the response of
the train. Use the graph paper to make your diagram accurate.
ii) Draw a spacetime diagram of all of this using the inertial frame that
matches the train while it is moving smoothly down the tracks. Be
sure to include the explosions and the response of the train. Use the
graph paper to make your diagram accurate.

Answer 1

The answer to your question is provided in the image: