We started by going over some conceptual problems on projectiles, and students seemed comfortable with the shape of the velocity-time graphs. At the end of whiteboarding, after doing the last question about calculating where a horizontally-launched projectile would land, a student asked me how to calculate where a projectile would land if it were launched at an angle. He started mentioning components of the initial velocity vector, and I had to hold my tongue. I didn't want to get lost in the math of projectiles this year. We used PHeT instead to simulate the launching of many projectiles. We came up with some pretty powerful conclusions, most of which were suggested my more than one student before I summarized them on the board.
