The Advanced Physics Homework Help forum is for upper-division (college junior or senior) and graduate-level questions. Other schoolwork physics questions should go in the Intro Physics forum.
If your thread mysteriously disappears without a trace from this forum, you probably didn't post it in the right place, so your thread was moved to the Introductory Physics or Engineering forum.
Advanced physics does not mean, among other things:
"I think this problem is really hard."
"I'm taking a college physics course."
"We're covering electromagnetism now."
"We're covering relativity now."
"We're covering quantum mechanics now."
If you have to plug numbers into a formula to get the final answer, that's usually a good sign the question doesn't belong here.
Questions that do belong in this forum are from upper-division or graduate physics courses — classes physics majors (in the US) take in their junior year and later.