Rube Goldberg Machine

For this project, we were tasked with building a Rube Goldberg Machine, a machine that completes a simple task in an overly complex way. The concept was popularized by American cartoonist Rube Goldberg who created cartoons of fantastically complicated machines which performed utterly trivial tasks. In our project, the machine was also required to have a theme to link all the machine's actions to a single idea or concept.

I was put in a group with 3 other team members. We started our build by brainstorming possible themes, and our group ended up deciding on a theme of gardening. Once our theme was established, we began drawing out a rough layout of our machine and deciding on the steps it would perform. Since our group's machine reflected a theme of gardening, our machine's actions represented each of the steps needed to successfully grow a strong flower. We now began building our machine. Due to the circumstances surrounding distanced learning, each member of our group completed one quarter of the machine individually and each section was then linked together into one cohesive video. Once the build process was completed, we created our final presentation (linked below) which covered our construction process, calculations, and other related analysis content.

The Presentation

Core Concepts

Acceleration

Acceleration is the rate at which velocity changes — it is the ratio of velocity over time. The metric unit of acceleration is m/s², "meters per second squared".

The acceleration of that same ball was 1.77m/s² (calculated as described above). This means that its velocity was increasing at a rate of 1.77m/s every second.

Potential Energy

Potential energy is a measurement of how much energy an object "has". The most common example of such energy is gravitational potential energy — a raised object will have higher potential energy than one on the surface, because it can convert more energy into kinetic energy by falling farther. This kind of potential energy can be said to be due to the object's position in the gravitational field.

Gravitational potential energy is equal to the mass of the object times the acceleration due to gravity times the height of the object above the surface. Because of this, potential energy is measured in Joules. Another interesting relation is that the change in potential energy over a period of time is equal to the work done on that object (over that period of time). This, too, verifies that potential energy should be measured in Joules.

Because the work done by the finger was 0.06J, we can say that it had a potential energy of (at least) 0.06J before pushing the lever. This comes from the fact that W = ΔPE, and therefore the potential energy must have been at least 0.06J to be able to do the work to move the lever.

Kinetic Energy

Kinetic energy is a measurement of an object's energy due to motion. For instance, a fast-moving car will have high kinetic energy, while a slow-moving turtle will have very low kinetic energy. Kinetic energy is equal to one half of the mass of the object times the velocity of the object squared — here we see the clear relationship between the velocity of an object and its kinetic energy.

Since the velocity of the marble at the end of section 1 was was 0.64m/s and its mass was approximately 0.0178N, it had a kinetic energy of ~0.022J at the end of the ramp. This comes from the fact that 1 / 2 · 0.0178N · (0.64m/s)² = 0.022J.

Simple Machines

A simple machine is one of six foundational "building block" machines that make an objective task easier. They are:

• Levers

• Pulleys

• Wheels and axles

• Screws

• Wedges

• Inclined planes

Our machine included 5 out of the 6 simple machines as required (it did not have a screw).

Construction Logs

A construction log is a record of the process of construction for a particular machine or other object. In our project, we each kept construction logs for our sections of the machine as well as for our final presentation. You can find our log in the presentation linked above.

Reflection

Overall, I believe that the project went fairly well for me. For one, I did well with the calculation of the physics behind the machine. I've always had a great interest in math and problem-solving, so the calculations fit right in to that critical thinking strength (one of the 6 C's). Additionally, I think the collaboration aspect of the project (from the perspective of my contributions to the team) went very well. I was originally not enthusiastic about the theme of gardening, but since the group wanted that theme I worked hard to make it the best I could. Also, throughout the entire project I was constantly monitoring our team's progress to make sure that we met the deadlines and got everything done on time. When it became clear that not everyone was going to get all the work in by the desired date, I did my best to try and help them out. Once they did get the work in, I worked as hard as I could to incorporate their material into the slideshow with the limited time I had while keeping our presentation as professional as possible.

However, the project was certainly not perfect. The biggest factor in this was inadequate planning. The initial blueprints were not very accurate and did not have precise measurements that would have worked in the real world. For this reason, construction of the machine was done very much ad-lib, and therefore the construction process was not very efficient (or fun for that matter). Therefore, I think the critical thinking aspect of the project had both a positive side and a negative side. In the future, I will definitely plan the project more carefully and more accurately. Additionally, I think the communication aspect of our project was mostly good but partially bad. Our presentation was fairly professional, but due to the adaptations we had to make to present it virtually there were a few unforeseen issues. To begin, my cursor was visible on the Zoom screen share, which I was unaware of because I had been under the impression that Zoom hid the presenter's cursor. This may have caused a distraction to the content of the presentation. Also, the videos were extremely jerky due to Zoom's buffering. I would have made the videos in slow-motion had I known of this so that the audience could see what was happening more clearly. Therefore, in the future I will do a careful "test-screening" of my presentation so that I make sure there are no technology glitches or issues.

While the project was definitely not perfect, I would say that overall it was a success. I definitely learned some important lessons that I will carry with me to future projects and any future presentation. I also had some successes, which I will learn from and try to emulate in the future.