Our Rube Goldberg Machine in action. The theme is Baking A Cookie.
Important Terms and Concepts:
Force (F=ma)- push or pull on an object. Gravity is a force. The car in our project put a force onto the marbles that made them move forward. Friction- While building we had to be conscious of friction especially in our pulley and wheel and axle. If there was too much friction then the pulley would stall halfway down the board. Mechanical Advantage Real (MAreal=Fload/Feffort)- How much easier a tool makes something. Although it is important to know how to calculate mechanical advantage real it is not relevant to a Rube Goldberg Machine. It is easier to find distances than forces. Mechanical Advantage Ideal (MAideal=deffort/dload)- How much easier a tool makes something. We used mechanical advantage ideal to find the mechanical advantages in our project. It was easier than real because ideal uses distances. It helped to know the mechanical advantage when estimating have big the axle should be for our wheel and axle and how inclined our ramps should be. Velocity (v=change in distance/ change in time)- The rate of covered distance in a direction. We used velocity to find how fast the marbles were moving and there for how much kinetic energy they had. This is important because it helps us gauge if the timing was correct (if the milk and the cookie would land at the same time). Acceleration (a=change in velocity/change in time)- The change in velocity (speeding up or slowing down). This also helped with our timing. Work (w=fd)- Amount of energy put into something. We used work for our split off. Both marbles started from the same height. They both had the same amount of energy. Then the marbles started moving at different accelerations. Potential Energy (PEg=mgh)- Energy an object has due to it's position at a height in a gravitational field. For example, we our car dropped from one track to another. Gravity pulled it down. Potential energy equals kinetic energy if no outside forces are in play (ex. friction) Kinetic Energy (KE= 1/2mv^2)- Energy an object has due to motion. All of our marbles have kinetic energy because they are moving. As they roll down the inclined plane their potential energy coverts to the marble rolling down the hill which is kinetic energy. |
Thinking back on this project I am satisfied with what my team accomplished. Our task was to build a Rube Goldberg Machine. A Rube Goldberg Machine is a contraction that takes a simple task and over complicates it by completing it after a series of steps. We were put into groups of four. My team's machine's goal was to put our "cookie" into the "milk". Since this is our first project we were also learning some basic vocabulary and concepts like Mechanical Advantage and Friction. Although it was hard to start the year off with this project it helped us gain skills that we will be able to apply to every other project we do during the course of the year. There were 15 project days total plus anytime we put in during lunch and after school.
Our first three days were planning days, during which we worked together to make a blueprint. First, we each made our own blueprint then we combined them to form our blueprint we were going to build of off. If you look at our "build off of" blue print below I came up with the idea to put the cookie in the milk via wheel and axle. I also thought of the idea to have two tracks running simultaneously. Then we had 9 build days to construct our final product from our blueprint. I started building the pulley, marked holes for where we needed to drill, tested different angles for inclined planes, made our third version of the wheel and axle, and started building the marble split off. In addition, me and one of my teammates attached a majority of the ramps, calculated how much water needed to be in the pulley, attached the small barriers to the sides of the ramps, and more. We were very productive especially during the last few build days. In the end we had 13 steps and 5 simple machines. In addition to the Engineering aspect of the project we also had to incorporate the principals of design. Finally, we had 3 more days to write and practice our presentation. During this time we still had some work left to do on our machine so two of us wrote the presentation while the other two finished up the project. This system worked alright. It would have been better to have all group members contributing to the format of the presentation. Then we practiced. The two group members who did not write the presentation got their opinion in during practice. The second day we practiced 2 times and the third day we practiced 3 times. Although we could have used more practice time I felt like we were prepared. When the final presentation night came I was nervous. We all came wearing professional clothing. My team did our presentation 3 times. Although our Rube Goldberg Machine did not work any of the performances we got close and I felt like afterword every group had something to be proud of. Each Rube Goldberg Machine was unique and had something special about it. I congratulate everyone for a job well done. Looking back at the project there are a few things I would have done differently. Specifically, managing my time better and adding more variety in the steps. At the beginning on the build time my team was productive then we got lazy. I wish we had used all our time to the fullest because at the end we were scrambling to get things finished. We could have used the extra time to improve our design aspect. I felt our design principle paragraph was forced and I would have liked to spend more time on it. In our project we used several marble ramps. After seeing other projects I have realized that there were so many possibilities other than marble ramps that I feel disappointed that we were not more creative. I am proud or our pulley. I think we had the longest pulley and were more ambitious with our wheel and axle and our goal. In the end, we were able to get these steps to work at least some of the time. I am also pleased with how our presentation went. I felt we were organized and had rehearsed more than other groups. we handled our machine not working well and just kept moving through the presentation. Because of this project I can now safely use saws and drills. I know how to find the right screw and how to test if wood can be drilled. I plan to improve my collaboration with my teammates and to give everyone a change to lead. I will also try to not be as demanding and more understanding of everyones capabilities. Overall, I am pleased with the final product. |