https://www.physicsforums.com/archive/index.php/t-77612.html here's a link to the same question which has already been inquired before by someone else. according to the question, it asks to calculate the "actual" depth and once I have read all the replies on that page, the author seemed to calculate the answer. I've tried it myself and acquired the same answer. However, I'm a little confused with the given unit "1.0m" in the question. Is it just there to confuse the reader? because it has not been included in any of the calculations. Sorry for posting too many questions :( and thank you in advance.