SOLUTION: A portion of a track for a roller coaster is supported by two beams of different heights. The 40 foot and 30 foot beams are perpendicular to the ground. Steel cables are attached f

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Question 1148993: A portion of a track for a roller coaster is supported by two beams of different heights. The 40 foot and 30 foot beams are perpendicular to the ground. Steel cables are attached from the top of one beam to the bottom of the other. How far off the ground do the cables intersect?
Answer by greenestamps(13200) About Me  (Show Source):
You can put this solution on YOUR website!


This is a classic problem with a simple answer. If the heights of the two poles/beams are a and b, and the cables are connected from the top of one to the bottom of the other, then the distance above the ground where the cables cross is

%28a%2Ab%29%2F%28a%2Bb%29

So with the beam lengths 40 and 30 in this problem, the distance above the ground where the cables cross is

%2840%2A30%29%2F%2840%2B30%29+=+1200%2F70+=+120%2F7

It's a good exercise using a bunch of similar triangles to derive that formula....