SOLUTION: Suppose a railroad rail is 2 kilometers and it expands on a hot day by 15 centimeters in length. Approximately how many meters would the center of the rail rise above the​ grou

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Question 1136270: Suppose a railroad rail is 2 kilometers and it expands on a hot day by 15 centimeters in length.
Approximately how many meters would the center of the rail rise above the​ ground?

Answer by MathLover1(20850) About Me  (Show Source):
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Given that the railroad rail is 2km before expansion.
When the railroad expands, it makes an isosceles triangle at the center of the rail.
The base of the triangle is 2km while each leg of the triangle is given by 2km%2B15cm=%282%2B+15%2F100000%29+%2F+2+=+2.00015+%2F+2+=+1.000075km.
[recall that 1km=100000cm , thus 15cm gives 15%2F100000km]
Taking one half of the isosceles triangle, we have a right triangle with one of the leg as +1km and the hypothenuse+=+1.000075km.
Thus, using the Pythagoras theorem, we find the other leg (height) of the right triangle as follows.
Let the other leg of the right triangle be h, then

h%5E2=1.000150005625-1
h%5E2=0.000150005625
h=+sqrt%280.000150005625%29
h=0.0122476784km
Thus, the center of the rail will rise 0.0122476784km above the ground.
But, there are 1000m in 1km, therefore, the center of the rail will rise 0.0122476784%2A1000m=12.25m above the ground.