You didn't say anything about apache and mod_jk in your 1st post. What I've posted above is to be used by tomcat standalone. I.e. to visit your webapp you need to use:
http://tomcat:8080/my-webapp.
Anyway if you changed the context path in tomcat, like in my previous post, then it should work too, using the url:
http://apache/my-webapp. Of course your mod_jk setup should already be working.