Friday, January 14, 2011

Marble Momentum

When first reading the question choices, I thought the answers seemed very obvious and did not know how I would be able to think about how inquiry would be at work. I was very wrong and probably ended up with more complexity than was necessary. I chose the question "How do different surfaces affect the momentum of marbles."
The first problem I encountered was how to apply the same amount of force on the marble to propel it across the surface. I started by flicking my finger against it, but realized there was no way to know for certain how much force was exerted each time. This meant I had to come up with some kind of launcher. I started looking through some of my kids old toys, like Hot Wheels race track, but none of them was an ideal fit. This meant I had to design my own marble shooter.

Designing the shooter fit in with the engineer design process because I had to plan, design, construct and test. I used a rubber band stretched across two nails in a board. I had to adjust how far apart the nails were and find an optimal point for stretching back the marble. It was actually kind of fun and my teenage kids got into helping me with it. Once construction was complete, I tested momentum on a hard floor, carpet, and bed. The results were what I expected, but I realized a lot more thought had to go into setting up the test.

I also learned more about impulse, the amount of time the force applied to an object. This was how long the marble was in contact with the rubber band the more it was pulled back. The more contact time between the two equalled great force and momentum. This was a bit of an "Aha" moment for me because I had a hands-on example of what had been explained in our text.

Through this inquiry experience, I saw how something I thought was very simple can actully turn into a more in-depth learning experience. For my seventh graders, I could have a bunch of materials for marble shooter building. This would incorporate EDP with inquiry. Even though I didn't go any further than momentum and impulse, the question could include further study of Newton's Laws. The possibilities are endless, but that can also be a problem. I would need to set limits on the number of concepts included in answering the question so it does not become too overwhelming or time consuming. However, students would definitely be encouraged to study further on their own.

Any time toys are used in the classrom, students see the relevance to their lives. It also makes learning more fun. From this activity I would like them to learn to ask questions that are testable, design a possible solution and draw conclusions based on their results. This turned out to be a lot more fun than I expected.

2 comments:

  1. Wow! I love that you put so much thought and care into controlling your variables. My students struggle with this aspect of experimental design. I used to do a similar experiment with my students and we used a ruler with a grove in it. The students would use the ruler and textbooks to create and incline and roll the marble down.
    I also liked that your family helped you with this project. I am glad you had fun.

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  2. I did the same inquiry, but did not have the same success as you. I didn't make a marble launcher which is a great idea, and I had the same problem. You seem to have solved the problem. I was having a hard time trying to find out what momentum looks like. You have painted a clear picture and for your students that will be half the battle. If they can see it, then they can achieve it right?

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