We had a long discussion about how to analyze forces at angles. When a person pushes a table at an angle, should we call that a normal force? A normal and a friction force? We decided that perhaps an applied force would be a way to sidestep this debate. We also debated which direction friction point. This even required, after I thought the discussion was done, a student call up another student to go through question 2 (pictured) after I thought we came to a class consensus. Hey, if I'm wrong, feel free to call someone else up!
Then I introduced two ways we can look at forces at angles--as components and through vector addition diagrams. I lamented we had a no way to quantify forces. So it was off to lab to figure out some quantitative relationship involving the force of gravity. We were creative about what objects we used as test masses.