Before beginning the trails on each surface, I made sure that I had enough space to allow each marble to travel the maximuim distance. I then made sure my launching pad was straight so that the marble would travel straight. As I launched the marble on each surface, I completed three trails per surface and averaged my data to get a medium result. During the experiment the smoother surfaces allowed the marble the travel greater distances than the rougher surfaces. I was able to see that friction is caused with surfaces that is not smooth. My results were what I had predicted, the smoother the surface the farther the marble will travel.
During the experiment the launching of the marble was not a problem because I had forseen this and built a launching pad so that the marble would basically get the same force for each trail. What did not work well was the distance that was traveled on the smoother surfaces. The distance was great and measuring it could become troublesome for my students. I would consider using time with them to ensure more accurate results.
I would make this experiment more fun for my students by having them design their own experiments, they would not have to use marbles or the same launching pad, I would allow them to explore how surfaces affect momentum in anyway they choose. The only requirement is that they learn the relationship between momentum and how friction affects the distance traveled.
I do feel that this experience is related to their lives because they encounter this relationship if they walk and especially if they play sports.
You really thought through this guided inquiry activity. I liked your idea of the launching pad to apply the same force in each trial. Marbles on smooth surfaces can travel a long way as a found out today!:) Do you think this inquiry activity would be as effective if you used another object that wouldn't roll as far?
ReplyDeleteI did this experiment as well, but I just used a ramp. I love the idea of plastic tubing! One of the problems we both seemed to share was the distance the marble travels on smooth surfaces. I, too, thought about timing the marble, but did you have any surfaces where the marble did not roll very far? Would you do "distance traveled in 5 seconds" or a different measurement?
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