This seems pretty fundamental to me, however I was not able to find information about this particular problem on the net, so I'm writing here seeking your knowledge
Let's say we have two connected perpendicular "tunnels" like in this picture:
Widths are x and y respectively. Question is, what is the maximum length of an indefinitely narrow object, which is able to move from one end to another?
Sorry for possible awkward presentation, English is obviously not my native language.