Golly, are you doing the project or is your 5th grader? It sounds like too much parent involvement here to me. This assignment's purpose is no doubt about educating your kid. If your child doesn't engage with coming up with a topic that is personally interest, what is the point? As an educator with 40 years experience in elementary education, I implore you to put this task back where it belongs, in your child's lap. You can help by providing feedback, asking questions about what is of interest, etc., but please don't look for someone else's prescription for a snap project.