More Projectiles, and Slope-Intercept Lines

Today in Mr. Ambrose's physics class, the students were doing a lab. In this lab, they dealt with projectiles fired at an angle. In the first part of the lab, they fired a marble with the "cannon" at a horizontal position, and used the point where it landed to determine the muzzle velocity. Next, they chose an angle, predicted where it would land based on the muzzle velocity, and fired it to test the prediction. Generally they did pretty well with their predictions, though they were a little off. Most of them see to grasp projectile motion fairly well, although there are still a few who are confused. One thing that I see is that some of them instantly start putting things into equations without ever asking themselves, "Is this equation applicable?" As an example, they have an equation for the range in terms of initial velocity and angle - but it only applies if the projectile is launched from the same height where it lands, which isn't always the case at all, and certainly wasn't in the lab. I tried to explain that you always have to consider what your circumstances are, and when a certain equation is valid, and I hope that came across. Generalizing what they've learned to new problems can be a challenge for some of them, though it's a critical skill that they would find useful in other areas.

In Ms. Colwell's algebra class, they're working with lines in slope-intercept form and graphing them. Most of them seem to be getting it pretty well - I helped a few with questions, but for the most part, they were doing OK.