Guided InquiryUsing Marbles

"Momentum equals the mass of an object multiplied by its velocity." (Tillery, 2008.) During this guided inquiry, I tested Newton's second law of motion. He stated that, "the relationship between the net force, acceleration, and mass that describes the cause of change in motion." (Tillery, 2008.

The focus of my guided inquiry was, "How do different surfaces affect the momentum of marbles?" (Laureate, 2012.) I designed an inquiry involving an inclined plane, two marbles of different masses, a ruler, and multiple surfaces for the marbles to cross during the investigation. The first part of the inquiry involved testing both marbles with a plain surface to demonstrate how the marbles acted without increased friction. Next, the marbles were released at coinciding times and travelled across the different surfaces and observed for any differences based on the increase of friction and surface.

The marble with the smaller mass travelled faster than the one with the greater mass over the plastic wrap. They both travelled equally as far over the plain paper, aluminum foil, and the plain surface. The marble with the greater mass travelled a further distance over the foam, cardboard, wax paper, and the polar fleece. I believed that the marble with the smaller mass would slow down as it passed over the foil, foam, and plastic. I also believed that the marble with the smaller mass would stop not far it began to travel across the fleece.  The results were not as expected with the marble with the smaller mass. I believed that there would be more friction present in all the materials. The majority of the inquiry went really well. The one thing that was a struggle was releasing the marbles at the same time to ensure that the same result would occur. To get the desired results, I tested each marble run three times.

If I were to repeat this inquiry, I would try to design a device that would include a gate that opens at the push of a lever in order to control the equal release of the marbles.

I would have prototype models available in a variety of ways to allow students the ability to create their own design. It may help them to visualize the direction they need to move in order to be successful. The students would be provided with a scenario regarding a new ramp that is being built from the highway into their school parking lot. The students job would be to decide which type of surface would slow traffic and create more friction to prevent speeding coming off the ramp into the school.

I would like for my students to gain an understanding of friction's affect on momentum and how friction can have positive benefits in their daily lives. Most of the time we talk about friction slowing us down in a negative way, but I want them to see it has benefical uses also. Yes, I think I did achieve this goal.