February 2010 Johnny F Phillip O  Purpose of Experiment: The experiment explores the different factors affecting pendulum motion. Hypothesis: The angle of release, the length of the pendulum's string, and the overall weight of the pendulum have an effect on how long the pendulum takes to complete on full swing back and forth--or period. Procedure 1. Attached a weight to a string and then the pendulum to a pendulum stand. 2. Set the angle of the pendulum and release. 3. Allow the pendulum to make 3 full swings and measure the period by dividing the allotted time by three. Do this three times. 4. Attach a heavier weight and then a lighter weight. Measure the period three times with the same method as the first time. 5. Return weight back to one the group started with, but change the length of the string to a shorter one and then a longer one. Measure the period three times with the same method as the first time. 6. Return length of string back to the measurement the group started with, but change the angle of release to a greater or lesser degree. Measure the period three times with the same method as the first time. Data     Analysis Analysis on Angle: The angle of release for a pendulum would not alter its period greatly because gravity exerts the same amount of force on it no matter what. The acceleration, no matter what its initial angle is, would therefore remain consistent. Analysis on Weight: Although one would assume the force of gravity exerted on the pendulum would have an effect, the weight of the pendulum had almost no effect on how long it takes to make a complete swing back and forth. Though a pendulum that possess higher weight has more gravity pulling on it, more weight means more mass and therefore more inertia. Twice the inertia means it would require twice the force for the pendulum to accelerate. Therefore no matter what the weight, the pendulum undergoes the same amount of acceleration. Analysis on Length: The length of the pendulum determines the length of the pendulum's path during its swing. Verdict: According to the observations made by the graphs, the length of the pendulum had the most affect on the period while the weight and angle of release had minimal. Summary By measuring the period of a pendulum that had a length of 40 cm, a mass of 50 grams, and an angular release of 30 degrees, the group was able to see each factors affect by changing each variable individually. Although the group expected the length and the mass of the pendulum to be a factor, it turns out that only the length affects the time it takes for a pendulum to make a complete swing back and forth. However, they were right in saying that the angle of release has nearly no effect on its period. Although experimental errors may not have this experiment 100% precise, it provides a great general understanding of pendulum motion. Sources of Experimental Error: Although no instance of human error occurred while the lab took place, some natural experimental errors might have altered the results of this experiment. Without some sort of machine to accurately measure the exact time of a pendulum’s full swing, having human beings measure the period with a stopwatch may have skewed some of the data. In an experiment where fractions of a second are of the utmost importance, such emphasis on human reaction cannot make the results of this experiment completely credible. Although it does provide a general idea of what affects a pendulum’s motion, the natural experimental errors does take away from the precision of this experiment. There was also no true indicator of where the center of gravity was for the weight. |
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I really like the setup of your website. The way you use bright colors against the dark background makes the page much more interesting to read. I think it might help if you added a little more information to your analysis of the effect of the length of the string by explaining why it affected the period the most. Otherwise, I thought everything was great; I like the way you analyzed each variable separately in your analysis and how all the writing was concise.
Shelley G
Excellent job guys, at first glance your website is very appealing with your theme and colors. As i further examined the data and analysis it was clear that this was a good concise explanation of the lab. However in your hypothesis you didn't make a definite decision as to which variable would affect the pendulum the most. But overall, your site is very well put together and does a great job of explaining and analyzing the lab. And I must say that i was deeply moved by that remarkable photograph.
I liked the clean layout of the website, it made it much easier to read and focus on the main points of the experiment. Everything looks great, although your hypothesis doesn't really predict anything - it is a statement and when written like that, it doesn't look like something you are trying to prove. Overall, I think it looks like you put a lot of time and effort into this and it really shows in the well written paragraphs.
Terrific work! Your site's design is as Mrs. Holmgren would say "aesthetically pleasing," especially with that lovely picture of the two of you at the top. Your use of color in both the titles and graphs reads that you thought about the general appearance of your site. One modification I recommend is the wording in your hypothesis. I had to read it twice to understand what you were trying to say. Other than that, everything about this site was clean and well organized. Bravo.
very nice. i like the graphs and how they are labeled very nicely. i liked how each part of the website had a different color scheme. But, the analysis needs to be explained more, and the graphs seem a little out of focus. but other than that great website.