I want to start this meta question as place where people can put links to well asked homework-like questions.
The point is that if not so good questions are asked then we will have a meta question to point people to - so they can go and see well asked questions. Qmechanic, Jim and others are very good at highlighting well asked questions, but I found it hard to search for them - so I thought we could add links here...
Kyle provided a useful link to homework and excercise questions that have been voted up the most on Physics SE.
The answers below have links to well asked homework and exercise questions.
NB: Only one link per answer please!