I have found some "solidwork" files on GC(is that a software?had not heared of it untill this very moment!),and I want to open them in rhino5,the software I normally use for 3d modeling..Is there a way?
to my knowledge there is no solution, the solution i have is to get Solidworks and then export as Stl and import in Rhino. or use datakit plugin for solidworks to export to rhino format.
As far as I know, you should be able to open .sldprt without a problem. I use Rhino 4 and it is perfectly capable of opening .sldprt. You just need to be aware that SolidWorks has the tendency to put multiple copies of the 'same' shape stacked into the same space. You can easily check this by trying to select the object you see: if you get a choice menu on what part to select, hover over the possibilities with your mouse: they should light up yellow. You should be able to find it out rather quickly this way.
Also, loading .sldprt files can take a dear while. Even quite simple .sldprt models can take up a minutes worth of loading: it seems like nothing happens, but after a little while, the parts of the model start to appear.
Have fun, and if Rhino5 does not support .sldprt yet, you probably have the beta, because I cannot believe it won't... :)