Rube Goldberg Machine: doing something simple in a very complicated way that is not necessary.
The past month Jacob, Mikey, Patrick and I have been constructing our Rube Goldberg Machines. We had about 20 hours of building time and about 5 hours of preparing for a presentation. First, my group had to decide what our end product should be. So we started with just brainstorming all the ideas then we came up with an idea where our objective is to drop an Oreo into the bowl of milk. Then we gathered more ideas and started drawing a blueprint of our Machine. When we were done with drawing our blueprint, we started building our Machine. Each day we took pictures and it is in the video above.
← Key for the calculations
Calculations for ↓each steps
<STEPS> Our Rube Goldberg Machine has 10 steps total. Our Step 1 is the Pulley System. We pull the string of the pulley to lift the gate to let the car go. Step 2 is the Inclined Plane. The car rolls down the ramp and it collide into the ball bearing. We used ball bearing instead of just a normal marble because it has more mass to it. And our Step 3 is the Screw. After the car hits the ball bearing, the ball bearing rolls down the spiral tube. Then we have the Pegs as Step 4. In this step, once the ball bearing comes out of the spiral tube, it hits a wall and goes down the pegs. Step 5 is the Lever. After the pegs, the ball bearing goes down a little tube and hits the class 1 lever, letting itself and the blue marble which is located on the other side of the lever to keep going. For Step 6 we have the Inclined Plane/Ball trap. After the ball bearing hits the lever, it rolls down and goes into a hole in the inclined plane. At the same time, the blue marble follows the ball bearing and once the ball bearing goes into a hole, it rolls over it. And our Step 7 is the Energy Transfer/Collision. After the blue marble rolls the inclined plane, it drops off and hits the curve, which speeds up to collide with the clear ball. Next, our Step 8 is the Wedge. The clear ball drops into the cup that pulls the wedge out from under the yellow marble. Step 9 is the Ramp/ Energy Transfer. In this step, the yellow marble falls down a tube(after the wedge is pulled out) and hits a golf ball down the ramp. And finally, our last step, Step 10 is the Oreo Drop. The golf ball rolls down the inclined plane and collides into the Oreo, causing the Oreo to drop into the bowl of milk. These steps are also shown in the power point and the video.
<Concepts> • Simple Machines: These are the basic mechanical devices such as the inclined plane, the wedge, the screw, the lever, the pulley and the wheel and axle. We used all of these except the wheel and axle in our Rube Goldberg Machine. •Mechanical Advantage: It is when you make the work easier by increasing the time, distance, or less force; it's the advantage of force given by the machine. Ideal MA- output force over input force Real MA- input distance over output distance. We calculated the MA of the pulley in step 1, and the pegs, step 4, the pulleys MA is 1 and the pegs average MA is 2.625. •Force:It is any push or pull exerted on an object. Force is calculated by multiplying mass and acceleration of gravity (mass • 9.8 m/s^2). It's measured in Newtons (N). For example, in our step 5, the class 1 lever, the force of the ball bearing on the lever is 0.13622 N. We also calculated the force of the blue marble when it's about to hit the clear ball in step 7 and we got 0.02N...
: •Work: It is done when a force that is applied to an object moves that object. When a force that is applied to an object DOESN'T moves that object, then it didn't apply any work. Work is measured in Joules (J). The formula for the work is W=Fd (Force • Distance). •Speed:Speed is the measure of how fast an object is moving in certain amount of time. Measured in meters per second (m/s). We calculated the speed of the car rolling down the ramp in step 2. So the speed of the car is 0.21875m/s. •Impulse: It is the amount of force that you are exerting on an object over a certain amount of time. You can calculate impulse with Force • time (impulse= Ft) In step 3, we found the impulse of the screw; it was 0.0012 kgm/s. Momentum=Impulse Ft=mv Unit: kgm/s • Momentum: force or speed of movement. In step 9 we calculated the yellow marble hitting the golf ball, and the momentum of the yellow marble is 0.0756 kgm/s. You can calculate the momentum with mass • velocity (momentum= mv). • Potential Energy(PE): It is stored energy in an object. It is calculated by mgh(mass • acceleration due to the gravity • height). The formula is PE= mgh. In our step 8, we were able to calculate the change in PE of the yellow marble. The yellow marble had potential energy of 0.0057 kgm/s^2 The Change in PE = The Change in KE Unit: Joules (J) • Kinetic Energy(KE): It's the energy in motion. It is calculated by 1/2mv^2 (1/2 mass• velocity^2). We found the KE of the Oreo drop in step 10(our last step); it has the KE 0.0172872 J. • Deceleration: It's the decrease in the rate or speed. We were able to figure out that after the blue marble roles over the ball bearing(in the ball trap), it decelerates 57% in speed. • Acceleration:increase in the rate or speed; the rate of change in velocity. The formula for the acceleration is a= change in velocity over change in time. And it is measured in m/s^2 (mass over second square).. The • Velocity: It's a speed with given direction. You can use V=d/t (distance over time) to find the velocity. It is measured in m/s.
<Reflection> Over all, I think my group and I worked pretty well on making our (consistently working) Rube Goldberg Machine; our project worked above 95% of the time. Although, I thought we could have improved on some of the parts of our project. My group and I made many mistakes and we learned many things from it. One of the biggest thing that I learned was working with people who has different personality and ideas. When we first started this project, it was hard working together as a group. We all wanted to do in our own way and we were lack of communications; this was one of our pits. I learned that without communicating with each other, you can never work together. Communicating and discussing about a problem really helps to solve the problem quickly and you can learn from each other. Throughout the time of working on this project, we learned to listen and share our ideas to each other and solved problems together to make our machine work. Also sometimes we divided into pair and worked on different steps to finish the project by the time and to have fair amount of work to do for each one of us. And when we finished our project, it felt like we came up with many good ideas and our project worked majority of the time. One of the pit that I encountered was explaining my ideas clearly. Through working on this project, I learned that I wasn't very good at explaining things clearly to others so I had hard time telling my group about my ideas. I got better as I did more and more but I still need a lot of practice to get better. Also, when we were working in the middle part of our project was our pit because some of the middle steps weren't working consistently. We spent around 6-7 hours on those few steps. However at the end, through all our ideas, we made things that we thought it was impossible, possible. Another pit was the time management. We finished our project a day or two after we were suppose to finish so we didn't get much time to prepare for the presentation. However, we worked together through so we were able to finish everything by the presentation night. And the peak that I encountered was using power tools. As a girl, I've never had a chance to use power tools before. And through working on this project, I was able to learn how to use power tools such as a drill, hammer, saw, etc. Another peak was talking and explaining something clearly and with confident in front of many people. On the presentation night, before we start presenting our project, I was really nervous and scared. And the first time we presented to the audience, I couldn't have eye contacts with the audience while talking. However as the night went on, I was able to have more confident, explained the steps clearly, and had eye contacts with the audience. Even though everything seemed really hard in the beginning, through many hardships, mistakes and training, I learned many things and I had really fun building Rube Goldberg Machine with my group. :)