Vector Torture

Note to myself for next year:

My physics courses generally start with basic definitions and equations of the terms of motion (like velocity and acceleration) so the students can describe how an object is moving.
From there we move into Newton's laws, with which a student can describe why an object is moving.

Then comes the fiasco of applying this knowledge in more than one dimension at a time. Vector addition is very difficult for these students. Even in my honors classes, only half of the students have had trigonometry prior to my class - I believe it is a corequisite course - so students are overwhelmed with the number of equations and relationships they have to use.

"I don't get it."
"What's the x component?"
"Wait... last time you used cosine, so why are you using sine here?"
"What are we trying to find, anyway?"
"I added the vertical distance to 9.8, because that's vertical too."

I think next year I will spend the first week or two introducing our use of trigonometry without any discussion of movement. If a line segment is placed on a graph from the origin to the point (x, y), can we find the horizontal component, the vertical component, the angle? Of course we can. And once they think of that process as a mathematical process - one of geometry, not of physics and motion - I suspect it will all fall into place more quickly.

I'll let you know next year.