Depends on what you're content is. Mortgages, depending on your layout 10 visitors. Myspace layout site, 100 visitors. However it's also harder to rank for mortgages than it is for Myspace in the serps
a decent website is a lot of word to only shoot for $1/day I'm sure there are easier ways to make $1...
You can make over a dollar with a single click from a visitor or it could take well over 10 clicks. It depends on your keywords and how targetted your traffic is.
Some keywords such as medical stuff can pay 50 cents a click or more. The variation for how much a click is worth with Adsense is silly.