Justine C. and Nicole D. February 4, 2010 Purpose: The purpose of this lab is to show which variable affects the period of a swinging pendulum. Hypothesis: Before doing this experiment, we hypothesized that any change of any of the variables would affect the period of the pendulum. Set-Up: Hanging the mass from the string that swung back and forth and measuring the angle with a protractor which we held to the base of the string's attachment to the apparatus, we were able to determine the time it takes for the pendulum to complete one period when affected by a number of different variables with a stopwatch. 
      Analysis: The results of our experiment tell us that the only variable that significantly affects the period of a pendulum is the length of the string. When we changed the mass and the angel of release, the changes we observed in the period of a pendulum were not significant enough for them to be considered factors that change the period of the pendulum. Although the periods were not exactly the same, the slight variations were most likely due to experimental error, which are listed below. Sources of Experimental Error: In this project, there were many sources of experimental error. First of all, we took our data on several different days, but we didn't use the same string which meant that we had to measure and remeasure the same length of string time after time. Although this would seem an easy task, we had a little bit of trouble getting it exact because the knots we tied kept using up different amounts of string. Another thing that probably threw our numbers off was the human error in timing. With Nicole saying "go" and Justine pushing Start, there was almost no way for the two to be exactly simultaneous. However, since Justine was the one pushing the button each time, the lag in reaction time should have been about the same each time she pressed go. Stopping the time at exactly the end of 10 periods was a challenge as well because we could only use our eyes to predict when the pendulum would start moving down into its next period. Using a protractor to determine the angle of release proved to be a source of experimental error as well because holding the protractor exactly perpendicular to the ground was problematic. Also, when we looked at the protractor from different angles, an angle that might appear to be 20 degrees from where we are wasn't actually 20 degrees, but was something else. All of these factors contributed to the experimental error in the data from our experiment. Summary: In our pendulum lab experiment, our goal was to see which variable changed the outcome of the period. We tested three different lengths of string, three different angles, and three different masses. Before performing the experiment, our hypothesis was that every variable would significantly change the period. After performing the experiment, we discovered our hypothesis to be false. The result was that the length of the string was the only factor that affected the period significantly. Of course, no experiment is perfect, so there were factors including inconsistent and inaccurate timing that contributed to the error analysis, but overall, the experiment went well. |
Good job on the graphs. I like how you guys placed the graphs next to the data tables, giving me easy accessibility! the only thing I didn't like was the lack of pictures. Personally I like alot of visuals and I think that would have made the site much more enjoyable. However, the site was overall a win, so CONGRATULATIONS!
Overall I thought that this lab report was excellent. The data was easy to understand and displayed well. The written statements were concise and to the point. I thought that they touched on every experimental error possible including the one about the protractor which was quite interesting and very insightful. The only problems were a few mechanical errors such as spelling and run on sentences. Aside from those things the lab was overall very well put together.
I really like how well-organized your project is and how easy it is to navigate around the site. Also, your sources of experimental error clearly states each source and exactly how it would affect your timings. However, your analysis simply stated that the length changed the period. It would be a good idea to explain what kind of change occurred. On the other hand, your graphs and data tables are very precise and organized. Good job!
The lab is well done and organized. I like how the procedure section was organized, it really gives the reader a sense of what happened. The graphs and data tables are well layed out, and it makes reading them easier. One small thing that I want fixed (and its probably only me) is either making the text a bit bigger to match the purple headers or making the headers smaller.
I love the theme and I also love the huge size of the title for each section of the lab, which brings more focus to the information. The website's information and data are organized well and the structure seems perfect. The Experimental Error analysis is exceptional for it's amazing detail and it touches on every single error that could have occurred. I would include more pictures or colors to brighten the website. I also suggest increasing the size of the graphs so they would be easier to read and grab the reader's attention more. All in all, this website is perfect and I had to inspect everything to find anything wrong.
Nice Job! The organization is clear and well done, and I love the purple theme you have throughout the report. Great detail. I really liked how the charts and graphs were together, making things really clear and easy to understand. Nice!
The lab is well organized and concise, which makes me want to continue reading it. I liked the format of the procedure because it gets straight to the point and is easy to follow if we were to repeat the experiment. While I enjoyed the experimental error section, I think there should be less about the human error, but you guys did a good job talking about the other errors as well. I think more pictures would improve the site, but I really like the theme and color scheme of your lab. Great job! -KatieW