How do different surfaces affect the momentum of marbles?

My assignment for this week was to select a topic and create a guided inquiry experiment to suit the topic. I decided that this would be fairly simple; chose a marble, get a ramp, chose a height for the ramp and find a measuring tape. I next decided to try the marble roll on carpet, tile floor, concrete and sand. (Living in Florida we have Lots of sand). 

First trial, I sent the marble down the ramp. Our cat was watching in rapt attention and pounced on the ball as soon as it hit the carpet. As we all know this introduced a new variable (add cat?) and we can only have one variable in our experiment. So I put cat in the bathroom and finished up with the carpet trial.

Second trial, I sent the marble down the ramp to see how it did on my tile floor. It hit my front door and bounced back. I tried twice just to make sure.  I had visions of my students running all over the classroom, leaping over desks and hollering about catching marbles so I decided to skip the trial on tile. 

Third trial I went outside with my little ramp, box, measuring tape and marble. I’m certain by now that my neighbors wonder about me, with my having checked out 14 little solar cars previously on the sidewalk in front of my house (I had to make sure they were all working, of course). I’ve noticed that my neighbors tend to veer wide of the sidewalk when I’m out doing my experiments. 

Fourth trial was on the sand across the street, now my neighbors were avoiding me completely.

Now my trials were done and I went in to write up my paper. Here are some questions from my professor with replies:

How could you make this experiment more fun, interesting, or engaging for your students? Actually any time they get to play with marbles is good with them. Fifth grade students believe they are the ‘big kids’ but they still like to play. One thing I would do is to put them in groups of three, with a leader, equipment manager and a secretary. They work better with assigned roles rather than every man for himself.

How might you design this experiment so that it is relevant to students’ lives? I would do this with a class discussion about friction and momentum on highways, why it is important to have some friction and what would happen if there were very little. How would it affect the momentum of cars? 

What specifically would you like students to learn from this experiment? I want them to learn that different surfaces affect the momentum of things that come in contact with them. Some surfaces hasten momentum and others slow it down. Essentially.  Did you achieve this goal? I don’t know as I haven’t done this with my students. I imagine that they would understand it, especially if I keep the focus on the topic and give all students a way to connect to the experiment.