SUMMARY
A Rube Goldberg complicated machine that exists to fulfill a ridiculously simple task. It works using a series of steps involving simple machines and energy transfers. When my group needed to choose a task for our machine, we chose to have it crush a can. The next step was planning the parts of the machine and creating our schematic. At this point, we knew how many steps, simple machines and energy transfers would need to be involved in the machine. We decided to start our project on a vertical board measuring 3 feet tall and for feet across. Additionally, we made plans to use the rest of the wood given to us to attach a thinner board to the bottom of out first board to create a stable foundation for our machine. Our first schematic consisted of levers, a funnel, a screw, several inclined planes,a pulley system, a number of wedges and a 1 kilogram weight.
Using our schematic, we quickly moved on to the building process. We started by attaching the base to the vertical board. With our foundation secure, we started to work on the individual pieces of our project. These simple machines also function as the steps of our machine. These are listed below.
STEPS OF OUR MACHINE
Step 1: Dominoes:
Our project started off using dominoes to set a weight in motion.
Step 2: Levers
The weight set off by the dominoes in the previous step then sets off a series of levers, having a mechanical advantage of 2.
Step 2 and 3: The Funnel
The marble mentioned in the last step rolls into a funnel, transitioning it into the next step.
Step 5: The Screw
The screw will then bring the ball downward with an acceleration of 1 m/s2.
Step 6 and 7: The Inclined Planes
Our next step is a series of 2 inclined planes. The ball falls down the first inclined plane accelerating at 2.2m/s2.
Step 8: The Can Falls
The ball rolls off the plane and hits a can, triggering the pulley system.
Step 9: The Pulley System
The pulley system is triggered with a mechanical advantage of 2.
Step 10: The Scissors Cuts the String
The scissor cuts the string causing the weight to fall onto the can.
PHYSICS CONCEPTS INVOLVED
Force
The push or pull on an object.
F=ma
Mass
Amount of matter in an object.
Velocity
The rate of distance covered in a direction.
V= change of distance/change of time
Distance
The amount of space between two points.
Acceleration
Rate of change in velocity.
a= change in velocity/change in time
Mechanical Advantage
How many times easier a task is with a tool.
MA= force without tool/force with tool
Potential Energy
Energy that an object has due to its position at a height or in a gravitational field.
PE=mgh
Kinetic Energy
Energy due to motion.
KE= 1/2mv2
With these concepts in mind, my group was able to calculate the force, velocity, acceleration, potential and kinetic energies of many aspects of our project. For example, to find the force of a falling weight, we simply used our equation for force and multiplied the mass of the weight by the acceleration due to gravity. Making these calculations really helped my group and I understand the math behind each step we built and plan ahead to maximize the effectiveness of our machine.
REFLECTION
Throughout this project, my group faced many problems, and achieved many goals. We had great ideas and awful mess ups. I think our greatest strength as a group was time management. Throughout the whole process, we were always on time and planning ahead. We finished our project quickly without rushing. For example, we were done with the building and working on our presentation by the tenth day. This gave us three days to work o
n our presentation, resulting in a clean and clear presentation. On the other hand, splitting up work between our group members was not an easy task. Often times, half the group was working on something while the others were just waiting to be given a task. This proved to be a problem because it was easy to become distracted while only part of the group was working on our project.
Personally, I learned some things about myself and gained a few skills along the way. For example, one thing I learned about myself was that I can be tired and drained at the end of the day. This resulted in my work ethic and participation weakening. In the future, I can work to improve this by reminding myself of the role I play in the group and remembering to look for opportunities in which I can help my team. Another thing I learned about myself is that at times I can be too controlling. Sometimes I would give too many tips or suggestions and insist on something being done a certain way. I can avoid this in the future by reminding myself that every member in my group deserves to be heard.
I will continue to improve on these things because I am sure that these factors influence my behavior in and out of the classroom. Although time management and planning ahead may be my strengths, I will try my best to stay energetic, listen to others and stay active. Overall, I really enjoyed this project and I believe it was a great way to start my journey in STEM.
PICTURES