I want to take a picture of a sword cutting stuff.

[table1349]

Normally these photos are done with a special high speed camera but you can set your Nikon on fast burst mode and lower the file size so it can go as fast as possible. You could hold the remote trigger in your hand as you swing the sword.
On my D5300 I'd go to 60fps video but I don't know if the D5000 will do video??