Over this unit, we explored about work and Machines, we were divided into 5 groups and make 5 presentations focusing on five different machines and how they work there were five machines, where is Lever, Wedge, Pulley, Screw, and Inclined Plane, Me, Claire, Hayden, and Amber were in one group and focused on Lever, exploring how it works. the experiments and research simplified “lever” for me, I actually learned a lot from this project, as well as other groups’ works.
About Lever: Lever is a machine consisting of a beam pivoted on the fulcrum, there are three classes of levers, the different class of levers do the different types of works, what they all do is increase the mechanical advantage, which means we are able to move the same load with smaller forces. reversely, as mechanical advantage decreases, we need to apply more force in order to move the same load, but most machines are designed to increase the Mechanical advantage (MA). There are three classes of levers, categorized by the locations of three points, which is the fulcrum, effort, and the load. the first class of levers has the fulcrum between the load and the effort, an example for the first is seesaw, the fulcrum is placed between the load and the effort.
the second class of lever has the fulcrum. the biggest advantage of the second class of lever is that it requires less force to move the load, an example for the second class of lever is nutcracker, 
as we see in this image, the effort point is placed on the handles, the load is placed between the effort point and the fulcrum, which means the nut would be the load since it is placed between.
The third class of lever has the effort between the load and the fulcrum, the disadvantage of the third class of lever is that it requires more force to move the same load. However, the load will move in a longer distance than other classes. an example of the third class of lever is a baseball bat. 
as it hits the baseball, the top of the baseball bat is the load, one of our hand that holds the middle of the baseball bat becomes the effort point, and the bottom of the baseball bat becomes the fulcrum.
Self-Reflection:
In our experiment, we used the second class of lever in which the load is placed between the effort point and the fulcrum to do the experiment. We were trying to test how how does the distance between the fulcrum and the load in the second-class lever affect the work it requires to lift up a 200 grams weight to 0.1 meters height. for the first trial, we placed the weight on 0.15 meter between the fulcrum and the load, distance moved 0.10937 meters also 0.10937 work had been done, our calculations were more accurate, it is approximate because the corrugated plastic was moving in a curve distance, but Claire calculated as accurate as she could. Next, we moved the weight to 0.30 meter, this time, it moved 0.10205 meter and 0.13607 word was being done, the data shows a rule, the more longer distance between the fulcrum and the load in the second-class lever, the more forces are required to move the same load (200g weight). In the third trial, the distance between the load and the fulcrum increased by 0.15 meter again, at this time ,the lever moved 0.10048 meter curvely and 0.18108 work was being done. From the data, as the distance between the load and the fulcrum increases, the distance that the weight will travel decreases; second, as the distance between the load and the fulcrum increases, more force is required to move the load and more work will be done.
In this experiment, our methods are not as valid as we thought, because there were many variables that could affect our experiment but some were uncontrollable, such as human errors and instrumental errors, our eyes levels could not be exactly the same as 10.1 cm. Instrumental error also occurred during the experiment because we might forgot to readjust the spring scale. It would be better if we used 2.5 N spring scale because it was harder to see the decimals from a 5N spring scale than a 2.5 N spring scale.
- What were your contributions to the success of your group’s lesson presentation? Be specific. What parts did you research, what parts of the experiment did you have responsibility for, what were your responsibilities for the lesson preparation and presentation? I think I contributed the most at researching background informations for lever, I researched about section 1 which is background information for our presentation. During our experiment, my responsibility was to stable the ruler straight and also see how much force was being done from the spring scale.
- Describe one part of this project that was a challenge? How did you respond to this challenge? One of the most difficult challenge for our group was facing uncontrollable errors, such as human errors, even though we couldn’t completely control it, but we tried our best to make the data as accurate as we could.
- Describe what you most enjoyed about the project? What part are you most proud of–that you say “WE DID GREAT”? I think the best part of this project was the experiment, we had a lot of fun during the experiment through building instruments and I learned the most from the experiment, such as the calculations used in our experiment.
- Long after this project has ended, what parts of the experience will you remember? (…“the nightmare is over, I have blocked it completely from my mind!”…hopefully not!) This is worth as a memory of mine, I think that I actually learned the most from this project, from my group mates, from the video we watched together.etc, we communicated a lot during this project so I’m pretty sure that each of us learned new things from this project.