differences between relative_url using Rails with Prototype or JQuery

My web app is deployed with Passenger in a sub-uri, http://www.mydomain.com/vacademy/
and I am displaying a player in a page
the swf is located in ../public/dist/flowplayer-3.1.5.swf

Using Prototype library I wrote a script :
  $f("player", "./dist/flowplayer-3.1.5.swf", {
and I don't have any problem to get the player installed from

but when using jQuery
$(function() {
  $f("player2", "./dist/flowplayer-3.1.5.swf", {
the .swf is not found as the relative url is based on the
controller ... http://www.mydomain.com/vacademy/mycontroller/dist/flowplayer-3.1.5.swf

is there anyway to bypass this behavior, not using a relative path or
getting the rails public path in js ?

thanks for your help