Soooo... now what? Transitioning into the curriculum

This the part of the year where I pause a little bit and wonder how the heck do I start the real stuff? I'm perpetually tempted to solicit from students even the most mundane of details, just to prove to myself that they are thinking. But the kinds of questions I'm prone to asking during lecture could be most accurately described as "fill in the blank" for which the context makes it painfully clear what the answer should be: This is not critical thinking.

Today I had a brainwave and since I didn't have a class until half way through the day I had time to make it happen, much to my relief. After setting up the concept chart and supplying them with details about position, displacement, and time, it was time to start thinking about velocity... since there's really not a whole lot you can do with those fundamental measurements (besides perhaps discussing their origins, the nature of the smallest increment, and personal applications, e.g. the length of one's stride or the time it takes to start & stop a timer).

So on to velocity we plowed, and here were the questions I posed in a ppt slide with instructions to work on the questions in groups:
1) What is speed in terms of the items on your concept chart?
2) In what units do we measure speed, and what do those units tell us about what speed is composed of?
3) Write an equation for speed based on your answer to the above.
4) Is this equation always true? When is it not? What are its limitations?

As far as I can tell all the groups came to the correct conclusions, but now I'd like to know which question was most helpful for the creation of the equation which they created?

I'm inspired to ask such a question because of my recent reading of The Teaching Gap, which describes (among other very interesting things) the value Japanese school place on multiple methods. They don't require that all students use the same method to solve a problem, but observe, rather, that statistically speaking certain percentages of students will be prone to solving a problem through a handful of methods. So, of course, I'm very curious to see the distribution of methods the students used to come up with the equation... or perhaps since they worked in groups, I'll have to frame it more like, "Which question helped you personally understand what the equation ought to be?"

Update on the Women in Engineering: We're about to start our first project, so I'll see if I can put together a post-survey regarding their enthusiasm. I'll let you know what I find. :)