A reflection on friction

  

My daughters and I explored the question How do different surfaces affect the momentum of marbles? 

During the experiment, we released the marble with a ramp we built from a marble coaster kit we already had. We tested how the marble would roll across chart paper, a blanket, a yoga mat, and a laminate floor. Tillery, Enger, and Ross (2019) describe friction as an opposing force that works against the motion of an object. This exploration will directly investigate the impact friction has on the motion of an object.

Our results included the following averages.

        laminate floor - 44 inches

        chart paper - 32 inches

        yoga mat - 5 inches 

           blanket - 5 ½ inches

  

I expected the chart paper to be the greatest distance as it was smooth and provided little in the way of obstacles. My laminate floor has cracks and water damage so I expected that would provide more resistance to the marble. The laminate likely had an impact on the paper due to the marble changing course and continuing with its new horizontal trajectory. The marble did not travel a straight path on the laminate but continued to move with mild path alterations as it continued forward. I expected the yoga mat to provide the most resistance but did not expect the blanket to be so similar.

    The ramp seemed to provide the same amount of force for each marble which went well. The ramp also caused the marble to take alternate paths due to a small incline we built into the ramp. Next time we may modify the ramp to not include the same incline. We had to do many releases over until the marble exited the expected path. Our cat disrupted the experiment as well. She pursued the marble and interrupted its trajectory a few times. 

I would choose a smoother surface for the experiment that would be less likely to impact the other variables. I would also make sure there was not a cat present for the experiment. The gif on the left appears to present an ideal environment as I described. 😂

I would set up this experiment for my students in a similar fashion. I would provide them with a choice of materials to experiment with so that they would have some control over the variables. I would set up a guided form for them to track data and use rulers for measurement in lieu of the measuring tape I used. Another option would be to perform the same experiment with toy cars. The students are very into matchbox cars and would enjoy experimenting with them. They would likely want to bring their own to show off during the experiment. The specific goal I would like students to understand is that changing a variable in an experiment can change the outcome. I would also like them to acquire an understanding of how friction can impact motion. My students are also English language learners.  I would like them to develop English and academic language through collaboration and inquiry design by creating a community of inquiry within my classroom (Nichols, Musofer, Fynes-Clinton, and Blundell, 2022)

Reference

 

Nichols, K., Musofer, R., Fynes-Clinton, L., & Blundell, R. (2022). Design thinking and inquiry behaviours are co-constituted in a community of inquiry middle years’ science classroom context: Empirical evidence for design thinking and pragmatist inquiry interconnections.  International Journal of Technology & Design Education, 32(5), 2527–  2551. https://doi.org/10.1007/s10798-021-09711-4

Tillery, B. W., Enger, E. D., & Ross, F. C. (2019). Integrated science (7th ed.). New York, NY: McGraw-Hill. Chapter 2, “Motion” (pp. 43-50)