This idea of the unit vectors will work with the calc based students since their book uses unit vectors.
The college physics book doesn't use unit vectors.
I'll try some of these suggestions..
I think I misspoke something or wasn't crystal clear and they latched on to the idea.
Okay what I think happened was I was trying to explain why when the ball was going up the acceleration was negative. I think I said that the acceleration is in the opposite direction of the ball.
So the students inferred that when the ball is coming down, the acceleration and the direction of the ball are both the same, giving a positive sign.
Somehow I screwed up ;p
As to the velocity and the acceleration at the top I keep hitting that hard. One student remembered over the weekend so that was promising. I will ask them again next class.
Thanks for the suggestions.
Tina
Tina Fanetti
Physics Instructor
Western Iowa Technical Community College
4647 Stone Ave
Sioux City IA 51102
712-274-8733 ext 1429