To prepare for this lesson, I gather a bunch of meter sticks, toy cars, balls, and building bricks.
I show my class about 10 seconds of kids bowling and then professional bowlers. I then ask them think about which ball has more energy, and how they know, then to turn tell a neighbor. I call a few students to share.
Next I demonstrate rolling a marble down a ramp and having it collide with a small object. I then present them with the focus question, "How can you plan and conduct an experiment to explain how speeds change when objects collide?" and then have them glue the Collision Course Student Investigation Sheet into their scientific notebooks.
I use guiding questions to help them refine their experiment designs.
As groups finish writing their procedures, I coach them to make a prediction that includes their variable and outcome.
I collect their papers at this point so that I can make sure their procedures will test their question effectively before beginning the experiment the next day. This also gave me time to gather any other materials they might ask for that I didn't think of.