Deeper to the muscle fiber is the sarcplasm which is cytoplasm in the muscle cells, this cytoplasm contains myofibrils which are just bundles of filaments. Now, myofibrils shorten, tis makes muscles contract and allows for movement. Some functions of musces in our bodies include motion, maintenance of posture, and heat production. Macromolecules that aid muscle contraction are the proteins myosin (thick filaments) and actin (thin filaments), the way that this is done is that they overlap each other and during contraction which makes the muscle “shorten”. Hypothesis:
As more weight added to the load that a muscle is lifting, the muscle will go through muscle fatigue faster. Prediction: If a person lifts two loads, one light in mass and another that is greater in mass, then the person’s muscles will fatigue faster when lifting the load with the greater mass. Materials: * Stopwatch * Two Books Procedure: 1. Have Person 1 hold a book in their dominant hand as they are standing.
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2. Now, Person 1 will now elevate the arm that they have the book in laterally (as if doing jumping jacks without the jumping), and they will bring it back down once their arm has leveled with their shoulder. . Person 1 will continue this exercise until they can no longer lift the book. (don’t forget to record how long they last with a stopwatch). 4. Now repeat steps 2 and 3 with Person 2 and Person 3. 5. After at least 40 minutes Person 1 will repeat the exercise with two books instead of a single book this time; Record their time. 6. Repeat step 5 with Person 2 and Person 3. Results: Weight(# of Books)| Time lasted until Fatigue (in seconds)| | Person 1| Person 2| Person 3| 1| 70| 46| 41| 2| 39| 10| 35|
During this experiment I noticed that when Persons 1-3 did the exercise they would start to feel some sort of discomfort in at least the first 20 seconds. They would usually start going slower in their exercise than when they initially started it. I also noticed their discomfort in their facial features; for instance, they would all tighten their lips. These are basically all the qualitative observations that I detected. Analysis: This experiment consisted of two variables, the amount of books (Independent) and the time they could last doing an exercise (Dependent).
The data shows that every person lasted more time doing the exercise with one book than with doing it with two books. Person 1 lasted 70 seconds with one book, but when he redid the exercise with two books he only did 39 seconds—a big difference in time. This same correlation was shown with Person 2 who lasted 46 seconds while exercising with one book, but when the exercise was done again, the time lasted was only 10 seconds. This happened again with Person 3 who did 41 seconds with one book, he did 35 seconds with two books.
Any errors that might have occurred could be a misreading of the stopwatch—I sometimes tend to rush an experiment to try to finish it quickly and maybe I misread the stopwatch a little. Also, another flaw that could have occurred during the experiment could have been not making sure that the exercise was done correctly—the lift of the book is intented to be until the arm is at the same level as the shoulder every time it goes up and down. Now when people start to get tired they don’t lift their arms all the way up, that is why it is important that someone is making sure that they do the exercise correctly.
Lifting it all the way is harder and more tiring than when it is only lifted a little—this could have had a small effect on the data, I don’t necessary believe that it could’ve been a big impact. Another thing that did affect Person 2 was that they had small hands so it was hard for them to hold two books in the same hand. They managed to go through with the exercise but they did mention that they were having trouble with it. It could also explain why their time was so low—she only lasted 10 seconds with the two books. Conclusion: Hypothesis:
As more weight added to the load that a muscle is lifting, the muscle will go through muscle fatigue faster. My data did support my hypothesis, as mentioned above all three people tested gave very similar results—lasting longer doing the exercise with one book than with two. This is because of muscle fatigue. Even though the experiment had a flaw with Person 2 and her ability to sustain two books at the same time, the data was not damaged a lot, since she did do less time with the two books than with one book. In the end, the data supports my hypothesis and shows how weight is a big factor in muscle fatigue.