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)      (Show Source): 
You can  put this solution on YOUR website!  
 
 
 
Given that the railroad rail is   before expansion.
 
When the railroad expands, it makes an isosceles triangle at the center of the rail.
 
The base of the triangle is   while each leg of the triangle is given by  .
 
[recall that   , thus   gives  ]
 
Taking one half of the isosceles triangle, we have a right triangle with one of the leg as   and the  .
 
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  , then
 
 
   
  
   
 
 
Thus, the center of the rail will rise   above the ground.
 
But, there are   in  , therefore, the center of the rail will rise    above the ground.
 
 
  | 
 
  
 
 |   
 
 |