I'm clearly not the first to voice concerns regarding homework questions. Most people here know this is not a check-my-work or give-me-the-answer site, and so don't ask poorly-phrased homework questions that aren't about a physics concept. But we still have a lot, especially from new users. There's been a lot of effort put into making sure people know about the homework policy, from the tour to the help center to meta. But there are still issues, such as this question, on which I spent a good amount of time trying to figure out what the OP's core issue was - only to have him/her suddenly announce that s/he knew the answer. Why, given all the effort that's been put in to the contrary, are we still seeing poor homework questions? Is there any way we can fix this?
The homework questions are predominantly from new users. They probably didn't bother to read any of the info about the site (does anyone? :-), and in any case they have nothing to lose by posting the homework question. There's no meaningful penalty and in any case often (too often) someone answers it. Just look at the number of questions closed as homework that have answers: many with accepted answers. As things stand, the posting of homework questions is an inevitable result of the existance of physics students.
The only way to stop homework questions would be to bar new users from posting questions directly. One possibility would be to require questions from new users to be approved by the 3k users, or another would be to block questions entirely until new users had earned some reputation.
I would guess both options would require changes by Stack Exchange. I would also guess that the Physics SE is unusual in its disapproval of homework. As a result I doubt the SE would be willing to make those changes. It would be worth searching the mother meta as I bet the issue of approving questions has been raised before.