For this project, our job was to build a Rube Goldberg Machine. We had to use five different simple machines, nine different steps and, four energy transfers. Our simple machines included the inclined plane, screw, lever, wedge, and the pulley. The first of our ten steps was activating the wedge from behind the board which would trigger the toy car down the inclined plane. The toy car falls into the cup beginning the pulley. The weight on the pulley tilts the lever and the marble falls onto a ramp. The marble then goes through the screw and and out onto multiple inclined planes. Then the marble hits the Nerf ball making it roll down a ramp, activating the domino staircase. The dominoes topple and the last domino knocks over the cup with dice achieving our final task (rolling dice).
Project History
Day 1- We assembled the two planks of wood and we drilled two stand on the top piece to support it, so we wouldn't have to hold it. Day 2- We attached our first inclined plane And put the pulley on. It took lots of trial and patience to put it on correctly. Day 3- We added the lever and created a platform for the weight of the pulley. We also applied a second inclined plan and decided to use a plastic cup instead of paper. Day 4- We drilled a hole through the plastic cup and we added finishing touches to the inclined plane. Day 5- We drilled two giant holes to stick the screw through, but we soon found out that the material for the screw was to big for the holes so we used a smaller one. Day 6- We spent the whole day working on the screw/pipe and doing multiple test runs. Our new pipe worked so much better than our old one! Day 7- We drilled the second piece of would to the top one and brainstormed ideas for it. We also attached barriers to different places to guide the marble. Day 8- We placed our two first inclined planes on the bottom piece of the project. Day 9- At this point we were running out of time so we split into pairs (Olivia and myself and Ben and Jared) to speed up our building. Ben and Jared worked on attached a tilted inclined plane and also adding more barriers for the marble. while Olive and Myself worked on building the domino staircase. Day 10- Olivia and I finished the domino staircase and Ben and Jared there part too. Building was finished for our machine so Olivia and I came in at lunch to decorate/ paint it. Day11- We made final adjustments where needed and did many test runs throughout the day. We additionally started on the calculations for the physics concepts.
Concepts
Force- Force is identified as either a push or pull. It is calculated by multiplying the mass and acceleration. The wedge gives a certain amount of force to keep the car from moving.
Acceleration- Acceleration is the rate of change of an objects motion. It is calculated by dividing the change of velocity by the change of time. The car accelerates as it goes down the ramp.
Mechanical Advantage- Mechanical advantage (MA) is the advantage in force given by machines. The MA of the pulley is one.
Torque- Torque is a twisting force that causes rotation. It is calculated by multiplying force and distance. When the weight of the pulley hits the lever, the lever creates a certain amount of torque to drop the marble onto the inclined plane.
Velocity/Speed- Velocity is speed with a direction while speed is without a direction. They are both calculated by dividing distance over time. The marble has a velocity and a speed as its going down an inclined plane.
Momentum- Momentum is the amount of energy a moving object has. It is calculated my multiplying the mass and velocity. As the marble is coming out of the screw, it has a momentum of 0.002 Newton seconds.
Toppling- Toppling is when an object's area of support is interrupted resulting in the object falling. When the Nerf ball hits the first domino, it pushes its center of gravity making it topple onto the next domino ,etc.
Kinetic Energy- Kinetic energy is how much energy and object has due to motion. It is calculated by taking half of the product of mass and velocity squared. When the car is accelerating on the ramp it has a certain amount of kinetic energy.
Potential Energy- Potential energy is how much energy something has in a certain position. It is calculated my multiplying mass, acceleration, and height. When the car is at rest due to the wedge it has potential energy.
Reflection
Building a Rube Goldberg machine was a great way to start off our journey in STEM. It was extremely fun to actually build from scratch our machines. Our machine wasn't perfect, but I think my group worked very well together. What I learned about myself was that sometimes when I have an idea, my peers may not always understand it which then I have to find a better way to explain it. I may not be good at verbally explaining but I noticed that when I used objects and physically put them where I wanted them then everyone was on the same page. I had the idea for the domino staircase, but at first no one knew what I was envisioning so I began to build it and slowly they all understood. I also learned that my ideas may not always be the best option. In our group, Ben had a different idea than mine for the lever. We tried my idea and it didn't work, then we tried Ben's idea and it did work. At that point I became to be more open with new ideas and will work on next time as well. Time management for our group was really hard. We had so many ideas that we wouldn't be able to decide, putting us a little behind each day. We had multiple ideas on hoe to place the screw. In result of that, we spent a whole day on just deciding where we would put it. Next time it would be better if we have a day by day plan so we always know what we're doing. Another problem was that we were not so great at communicating. Some people wanted to have our ending product be putting dog food in a dog dish and one person wanted to roll Bokugon. We eventually agreed on rolling dice. On future references I think it'll be better if we all share our ideas first and put them all into consideration before we start to build.