During our project, we faced many difficulties and there were some arguments between our team members. At first, it was difficult to find a theme for our machine that we all agreed on, but eventually we decided to make our theme historical events. At about day five, we couldn't decide if we should keep the historical events theme or make it more fun and change it to a Christmas theme. We eventually decided to keep it as it was. Our final machine had five out of the six simple machines. We used a wedge, inclined planes, a pulley, a screw, and a lever, but we didn't use a wheel and axle. Our final goal was getting a marble into a mini basketball hoop. Our steps were the dinosaurs going extinct, ice age, cavemen, the Greek Empire, the Renaissance, the Titanic, Walt Disney, the Civil Rights Movement, and the Warriors winning the NBA Championship.
Work Log:
Day 1: We made the first ramp/start of the machine and attached an inclined plane. Also, we were still coming up with ideas for the rest of our machine. Day 2: We started to make the pulley system but we couldn’t quite figure out how to make it work. Also, we added on a flat piece of wood and considered the idea of putting a tube in the shape of a screw and how to connect it to the board.
Day 3: We drilled large holes in the board that we could put the tube through so it could leave the tube and hit the lever. We made good progress. Also, by that point we had about three simple machines. Day 4: We put down a wood block and we put a notch in it to make sure the ball stayed still. Also, we made it so the lever hit another ball then it rolls down an inclined plane. Day 5: We basically discussed this day whether to switch the theme for our machine or not. We also started updating the blueprint. Day 6: We used this day to adjust the different parts to work so that we could make sure the machine works well. Day 7: We put a ramp and another piece of wood towards the end and worked on some of the decorations.
Day 8: We put up 4 small blocks of wood for the marble to bounce off of, and a ramp.
Day 9: We put up a small funnel for the last step, and decorated the board.
Definitions:
Force: In physics, force is something that causes a change in motion of an object. The equation to find the force of an object is to multiply its mass by acceleration. In our Rube Goldberg Machine, we had one marble drop on one side of a lever. It had enough downward force to make the other side come up and hit a platform that another marble was resting on.
Work: Using a force to move an object a distance is called work. The equation to find the work of an object is multiplying its force and distance. When the marble goes into the cup on our pulley, it is doing work.
Velocity/speed: Speed is a way of measuring how fast something is moving or being done. Velocity is the speed of an object in a given direction. These are both solved by dividing distance and time. When our team's marble was rolling down an inclined plane, it had a specific speed and velocity.
Mechanical Advantage: Mechanical advantage is the ratio of the force produced by a machine to the force applied to it, used in assessing the performance of the machine. You find the mechanical advantage by dividing the input distance by the output distance. The pulley system included in our machine gave us a mechanical advantage of two.
Potential Energy: Potential energy is the energy of an object in a certain position. PE is found by multiplying the mass, the acceleration due to gravity, and the height. When any marble is resting on a platform, it has potential energy.
Kinetic Energy: Kinetic energy is how much energy an object has due to motion. Kinetic energy is found by multiplying 1/2 mass and velocity squared. When any marble is rolling down an inclined plane, it has kinetic energy.
Acceleration: The rate of change in an object's motion is called acceleration. It is found by dividing the change in velocity and the change in time. When a marble is rolling in any direction, it has acceleration.
How our machine works:
Step 1: The "Comet" rolls down the ramp ( representing dinosaurs ) Step 2: The ball goes down another ramp and falls into a cup Step 3: A piece of wood is lifted on the pulley system and lifts another piece of wood with a marble on it ( represented during the time gap between dinosaurs and ice age ) Step 4: The marble rolls down a platform ( representing the ice age ) Step 5: The marble rolls down a pipe ( represents the cavemen ) Step 6: The marble hits a piece of wood on another platform of wood with another marble on it ( represents ancient Greece ) Step 7: The marble goes down a ramp ( representing titanic and Walt Disney ) Step 8: Both marbles roll down a series of pieces of wood ( representing civil rights ) Step 9: Marbles go down another platform Step 10: Marbles land in a basketball hoop as our final task ( representing the warriors NBA championship in 2017 )
Reflection:
Since the Rube Goldberg machine was my first project in STEM, I was a little nervous the first week. But I realized there isn't really anything to be nervous about, and I even made a good friend along the way. I contributed some ideas for our machine, although some days I realized I didn't try as hard as I should've and I sometimes got off track. After our collaboration, I feel I did much better. I worked harder to contribute more ideas, and showed more empathy. Instead of getting mad when someone broke or lost something, I helped find it or make a new one. I also really loved Rube Goldberg night. It was really fun, I enjoyed watching other groups' machines and presentations, and I think my group did pretty well that night.