My eleventh graders took the practice ACT today in school, which meant I had one, solitary senior in my class for half of today. The juniors unsurprisingly came to class in a combination of gosh-that-test-was-hard and I-can't-stop-speed-reading modes. Not much was accomplished. We went over a fluid flow problem that was assigned for homework. It took a long time to whiteboard, and I wasn't going to push it today. The problem seemed relatively straightforward until we got to part d. We hadn't done a projectile problem launched at an angle before, but it was great to see the students step up to the challenge. The first board I showed above nailed it, and the second board only had one problem in the quadratic which was fixed. (The acceleration due to gravity had to be negative.) We talked about the strengths and weaknesses of each method.