![\"\"](\"/userfiles/image/steps_images/step1.JPG\")
The vertical cross section of a tunnel can be modeled by ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=9ad7b3445df115c1a39fd485becb045a.png\")
on![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=2b13cef9eb10560e611c9bfbde762e5a.png\")
.
The volume of the tunnel can be calculated by using ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=a2c05fdd3f9f0dc24c4fd0c422b0b677.png\")
.
where ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=f4227bbb7a6b6af2de948f1db3af23a8.png\")
is the length of the tunnel.
In the formula ![\"\"](\"http://www.mathskey.com/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=a2c05fdd3f9f0dc24c4fd0c422b0b677.png\")
the integral gives the area of each cross section.
Multiplying this area by the total length of the tunnel would compute the volume of the tunnel.
\![\"\"](\"/userfiles/image/steps_images/solution.JPG\")
In the integral gives the area of each cross section.
Multiplying this area by the total length of the tunnel would compute the volume of the tunnel.