"A" IN SCIENCE
'(<a href="http://www.j-archive.com/media/2006-04-20_DJ_08.jpg" target="_blank">Jon of the Clue Crew reports from Duke University in Durham, NC.</a>)  Vaulters can use hollow poles to save weight because this center line of <a href="http://www.j-archive.com/media/2006-04-20_DJ_08a.jpg" target="_blank">a bent pole</a> is neutral, taking little or no stress'
the axis