Is there any way to open solidworks 2011 files in Solidworks 2010?

The only way is using a Parasolid format, STEP or IGES.

The other way is to install a copy of newer version along the 2010, then, open the 2011/2012 version and save as parasolid and open in 2010, but I advise strongly against doing so. To make it work, you'd need a separate partition with a separate OS with a proper standalone SW installation. That means dual boot.

http://grabcad.com/questions/how-to-convert-solidworks-2011-part-file-to-older-solidworks-files

you can use the free online https://www.onshape.com/ or http://mecsoft.com/visualmill/ to convert files to stp, parasolid or iges. then open in solidworks.