The a very long suspension bridge is the Humber Estuary bridge in England, just short of 1 mile long between the supports. The two towers are not quite parallel. They are 1.375 inches farther apart at the tops than at the bottoms. Why?
2006-12-04 07:34:47 · 7 answers · asked by Anonymous in Science & Mathematics ➔ Geography
I'm not positive on this answer, but I think it's a pretty good guess. For a very long bridge, the distance between the tops of the towers should be greater than their bases. Assume both towers are perfectly plumb (straight up and down). Due to the fact that the earth is round, the center lines of these towers would be moving away from eachother as they got taller.
You can demonstrate this by taking a piece of paper and drawing a circle on it about 4" in diameter. Put a dot where the center of the circle is. Now draw a line from the center of the circle to about an inch outside the circle. Draw another line about 30 degrees from that one, once again originating from the center of the circle. Both of these lines are "plumb" with the surface of the circle, but if you measure the tops and the bottoms, you'll see that the distance is greater at the top.
Hope that helps!
Brian
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2006-12-04 07:40:43 · answer #1 · answered by Volckhart 2 · 1⤊ 0⤋
The brick masons were having a tail gate party and they let the plumb bob slip just a bit. Actually in the real world it is very hard if not impossible to build two towers parallel one mile a part or even a few meters apart. This is just the way the real world works.
Remember there are no hard questions, just questions that you dont know the answer to or the solution has not been found. Once the solution has been found, it is an easy question
2006-12-04 15:45:06 · answer #2 · answered by Anonymous · 0⤊ 0⤋
I like Volckhart's answer better than mine, but here goes anyway. I was going to guess that it was either related to (1) keeping the bridge from resonating and failing violently (Google "Tacoma Narrows Bridge" to see what I mean), or (2) to account for loading -- the bridge supports are not parallel when there's no load on the bridge, but when you add the weight of traffic, the supports bend inward slightly (as a cantilever) toward vertical.
2006-12-04 15:47:49 · answer #3 · answered by pluck_tyson 2 · 0⤊ 0⤋
Because that forms a slight triangle. And Triangles are the strongest shapes. Also, the beams/towers could be thicker at the bottom, so that the weight is more equally distributed.
2006-12-04 15:38:19 · answer #4 · answered by a_little_syco 2 · 0⤊ 0⤋
To take into account the curvature of the Earth.
2006-12-08 14:50:18 · answer #5 · answered by zekkmarshall 2 · 0⤊ 0⤋
It's the curvature of the earth
2006-12-04 15:38:09 · answer #6 · answered by rchlbsxy2 5 · 1⤊ 0⤋
rchlbsxy2's answer is the one correct one
2006-12-04 16:29:58 · answer #7 · answered by Scythian1950 7 · 0⤊ 0⤋