This would mean that it went 5 km for 10 seconds
5 x 10= 50km during that period of time
They begin to form about 3.8 billion years ago
Both seta and cheta or chaete means bristles. I think the term can be used interchangeably . Just check this link:- http://en.wikipedia.org/wiki/Polychaete It about polychaetes a class of annelid worms. These are extracts form the passage:- Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called *chaetae, which are made of chitin. Indeed, polychaetes are sometimes referred to as bristle worms. Bundles of bristles, called *setae, project from the parapodia. http://en.wikipedia.org/wiki/File:Polychaeta_anatomy_en.svg Thats a cross section the terms have been used interchangebly.
This should be the answer for the Krebs cycle
