Hi Guys, I need some advice/help. I am a undergrad at Columbia University, and am in my first semester, with an intended major of Astrophysics. I had my first midterm a month ago, where I got a decent 80%, and my homework grades were pretty consistently around that grade too. I go to Lectures and the Office hours, I even goto the TAs Office hours, and average roughly 10hours a week per physics problem set. And I did study for my 2nd Physics midterm and thought I understood most of the materials pretty OK when I went to do my 2nd Physics midterm. Which was why I'm in shock that the score of the 2nd midterm is around 50%, because it came out of the blue. I actually did not think that the midterm was that hard either -- difficult but do-able. So I'm not even sure what I did wrong. Has anybody else ever experience something like this ?