A Rube Goldberg is a complex series of steps to complete a simple process; such as watering a plant or turning a page. Over the course of 15 days, my group and I completed the not-so-simple task of putting a Mento into coke. We started our project by making a schematic and carefully measuring our plan. Our original idea was to take a polaroid picture, but we quickly discovered it wouldn't work for us. As soon as we could, we began to build our new idea of mentos and coke, starting with the foundation of a 4x4 piece of wood. Starting from the top and working down, we carefully added step after step and brought in all the needed supplies such as balloons, a nerf gun, paint, and of course the soda and mentos. We came across a few problems in our work, such as incorrect supplies and the failure of our original plan. Once we had completed the steps, we painted the entire project and perfected each step to get our desired outcome. Our last step was to calculate all the measurements and energy transfers throughout the project.
Acceleration
Acceleration is the rate of change in velocity, either speeding up or slowing down. To find acceleration, you divide the change in velocity by the change in time. The unit for acceleration is meters per second squared. I used acceleration on the second lever in my project. I started off by finding the mechanical advantage of the lever, which was 2. Then I found the acceleration due to gravity which is 9.8 meters per second squared and divided it by 2. My final answer was that the acceleration was 4.9 meters per second squared.
Force Force is the push or pull on an object that usually causes a change in motion. It's measured in Newtons (N) and is found by multiplying mass by acceleration. I used force on the nerf gun shooting the balloon. To find the force, I first multiplied 9.8 m/s by 1 kilogram. Then, I divided the mechanical advantage by the slope of the inclined plane (1.67) and got 5.9 N as my final answer.
Velocity
Velocity is the rate of distance in one direction. In the project, we used velocity in a few different steps. To find out how fast the ball was rolling down the lever, I first timed how long it took for the ball to roll down the length of the lever (0.6 seconds). Then I measured the length of the plane, and got 0.4 meters. I divided the two and got the average velocity of 0.66 meters. To get the final velocity, I multiplied that by two and got 1.7 meters per second.
Work Work is the amount of energy put onto something. It is found by multiplying force by distance, and is represented in Joules. We used work to find the amount of energy needed to pull the trapdoor and release the Mento into the Coke. Using the potential energy formula, we took 0.05 kilograms times 9.8 meters per second squared times 0.15 meters. The work of the weight amounted to 0.74 Joules.
Mechanical Advantage
Mechanical advantage is how much easier a tool makes a job. Mechanical advantage was shown throughout our project in simple machines like inclined planes, pulleys, and a screw as well as a dart and a pegboard. To find the MA of the simple machines I had to divide the length by the height. In the dart the MA was found by dividing the length by the width.
Potential & Kinetic Energy Potential energy is the energy that an object has due to its position at a height. It's measured in Joules (J) and is found by multiplying the mass and acceleration due to gravity times height. First, we found the potential energy of the ball at rest in the balloon. We multiplied 0.28 kilograms by 9.8 meters per second squared times 0.15 meters. Our final answer was the potential energy of 0.4 Joules. Kinetic energy is due to any kind of motion. To find kinetic energy you must multiply the mass and squared velocity. Then, you divide it by two and get your answer in Joules. We decided to find the kinetic energy the mento has right before it lands in the coke. I divided 0.4 meters by 0.3 seconds to get 1.3 m/s. I then multiplied that by 2 to get an outcome of 1.7 m/s. Then taking the 0.3 kilograms, I multiplied that by 1.7 m/s squared, and finally took 0.087 and divided that in half to get a final answer of 0.17 Joules.
Reflection Overall, our project was a success. Even with all the challenges and obstacles that came up, we were able to make it work just as we had envisioned. My personal peak during this project was being able to fix the peg board and come up with new and improved ideas to get everything running smoothly. I gained a leadership skill which was new for me, and I learned what it was like to keep everyone on task and have my own ideas listened to. But it wasn't always easy, we did have some low points along the way. Our first idea to take a polaroid picture didn't work, so we had to completely change our ending steps and recreate a different outcome of using the Mentos and coke. Another problem we had was when I accidentally bought the wrong size tubing without enough time left to buy more, so we had to build a screw for the ball to roll down instead. Even with the highs and lows, we created a project that turned out exactly how we wanted it and was able to run smoothly almost every time.