My own daughter asked - only two days ago - "What is physics"? While that may be a little too simple - there's plenty of definitions easily available - how simple can (or should) we go on this site?
I think it would be pretty difficult to create a question that is considered "too basic" from every perspective. After all, questions that on the surface look basic often pose much deeper questions. Physics, after all, is about the fundamentals. None other than Einstein spent much of his youth thinking about problems the average person would probably take for granted; and he gave us relativity theory.
"What is physics?" is actually a surprisingly pertinent question. Your average person certainly couldn't answer it well, and some physicists may even struggle to precise about it. "The study of energy and matter" is a common answer given, though somehow it doesn't fully justify it. Physics, especially these days, often blurs with mathematics at one end and philosophy at the other, not to mention chemistry and the more obvious ones.
Why don't we encourage posters to give a little bit of their background and their own thoughts? That way, we can address answers to an appropriate level, and also remind ourselves that we once had similar "basic questions" as well...
Simple rule: if a satisfactory answer can be provided by a simple Wikipedia query, it is too basic.
I think something is too basic if a reasonably-informed Google search will turn up a valid answer on the first page. I often wonder myself if some of my questions are too basic, like my last question:
Since I wrote that, I discovered that Wikipedia does, in fact address it. But the thing is, it's not addressed specific to what I had in mind, it's not as expansive or detailed as what I was asking for, and it would be hard for someone looking for it to find. Because of this, I think there's still a lot of value coming out of my question. But the question of whether or not something is too basic does occur to me a lot.
So here is a variant of the question that I think the OP is asking: should this be more like MO level or MSE level? I personally committed on Area51 because I think the physics community should get in on the type of stuff that can happen on an MO type site. I doubt that I will be asking questions on here for very long simply because I expect most of my questions to be too basic. That is the way it should be. Simple questions should be left for another site, except that it took so long to get this beta underway it may be detrimental to the community to turn people away. A lot of people think that MO is a bit snobbish, but they are missing the point, the website is for research level questions only. Or at least something that you might wonder about after qualifiers or some such thing.
Maybe a better example of a basic question would be the following: "I don't get free body diagrams, can someone please help?" I think this should be considered too basic, but I am not even the type of person this place is for so... those are my thoughts.
PS: MO is Mathoverflow and MSE is Math.stackexchange.
@Herb, physics is a natural science which studies processes whereby substances do not undergo change in their identity. For instance, melting ice is a physical process because it dies not change the identity of the substance water. You can go back and forth from water to ice and back without changing the identity of the substance water. You can even turn it into steam and then condense it back into liquid water. Identity is preserved.
Not so when chemical processes take place. Take for instance paper. You can burn it and what you get are ashes which are of a completely different identity compared to the paper you started with. No need to say that you can't convert ashes back to paper. Thus, chemistry is a natural science which studies processes which lead to change in the identities of substances unlike what happens as a result of physical processes.