Rube Goldberg Overview

What is a Rube Goldberg Machine?

A Rube Goldberg Machine is a machine that allows you to complete a relatively simple task in a very complicated and indirect way. Some of these simple tasks include turning on a light, pouring coffee, or pulling over the covers on a bed. Rube Goldberg machine are meant to look fun and interesting illustration-wise. They can consist of almost anything and they can come in many sizes, shapes, and arrangements. Every Rube Goldberg Machine is unique and they all have their own special features.

The Assignment

Our task was to design and build a Rube Goldberg Machine from scratch with our table groups. My group consisted of Katie, Ben, and I. The machine had to have at least 10 steps to it, and we also had to incorporate 3 elements of design, 4 energy transfers, and 5 simple machines. The final step of the machines had to be a simple task that we do in everyday life, but we had to show how our Rube Goldberg Machines made that task more complicated.

The Process

The first part of making this machine was to find a topic/theme to work with and build upon that. Our group chose to do A Day in the Life of a High Schooler. We then had to create a blueprint of our machine and plan it out. Next, we started our building process. The machines were constructed on a piece of wood that was 4 feet by 4 feet and they could stand vertical or horizontal. The building took place in our school's maker space, which consists of many pieces of various material to work with and appropriate tools. It took around 9 days to finish, but by then our machine had begun to look pretty good. Once we got back to our normal classroom, we had to find calculations for the steps of our Rube Goldberg Machines. These included velocity, acceleration, force, kinetic energy, and more. After, we did finishing touches and created a presentation. The next week, all of the groups did an evening presentation at school, split up into various classrooms. The presentations included stating what the steps were, the information and calculations of the steps, and finally, running the machine.

Original and Final Blueprints

Steps and Calculations

Our 10 Steps and Calculations

For our calculations, we used many different physics concepts. Those concepts are stated in our 10 steps. If you would like to see what the concepts are and how to find them, scroll down past the ten steps.

Step 1: Waking Up

The very first step in our Rube Goldberg Machine is waking up like you would in a normal day. To do this, we had a hole cut in the top left corner of our board that a large weighted marble rolled through. It would fall about 0.05m before hitting a ramp. It would then roll to the right for about 0.86s. Next, we found the distance of the ramp to be 0.24m, so we calculated the average velocity of the weighted marble to be 3.58 m/s. Finally, we took the velocity and the time to find the acceleration of the marble and came up with 4.16m/s^2.

Step 2: Turning Off Alarm

Our next step is turning off an alarm. To show this, we had a lever with a toy hand come up and stop abruptly like it hit the alarm. The lever we used was a PVC pipe cut to the right lengths. We then screwed a hole in the lever closer to the left side. We did this so that when you push down a little on the left (shorter distance) side of the lever, the right (longer distance) side of the lever will move over a larger space. After screwing the PVC pipe, we glued on a hand to "turn off" the "alarm" on the right side, and a metal cup on the other. The metal cup was used to catch the weighted marble from Step 1 as it rolled off the ramp. Inside the cup, we put in a few weighted rings to add some mass to that side of the lever so when the ball rolled into the cup, the cup side would go down and the hand would go up. The distance on the left side of the lever from the edge to the fulcrum was 0.08m and the distance on the right side was 0.22m. We found the Ideal Mechanical Advantage of the lever to be 0.36. That number may not be much, put it helps make the lever more efficient in even the slightest bit.

Step 3: Walking to the Bathroom

For our third step, we showed walking to the bathroom to take a shower. We did this by having a small weighted marble sit on top of a few weighted rings and have the lever tilt so that the marble rolled across the lever and it fell onto a piece of wood painted to look like a bathtub. To do this, we made another lever that also had the left side as the shorter side and the right side as the longer side. The one major difference between this lever and the other is that the first one made the right side go up, and on this one, it goes down. We found that the distance of the lever was 0.19m and that it took the 0.0084kg marble 0.55s to roll across the lever, so we found the velocity to be 0.35m/s. With the velocity and the mass, we then calculated the kinetic energy of the marble rolling on the ramp and it was 0.00051J.

Step 4: Taking a Shower

After the marble rolled off the piece of wood, it fell into a bathtub. Then, it would roll down a spiral that looked similar to a pipe for the shower drain. This was to show taking a shower in the morning. The piece of wood that the marble fell onto had a hole in the center that it would roll down. Once it fell down the hole, it would roll through a pip twisted into a spiral. At the end of the spiral, the marble would come out onto a piece of wood that acted as a ramp, and it would continue on. The pipe that we used was about 1 meter long, and it took the marble around 1.45s to reach the end of the pipe after it fell through the hole. We then calculated the average velocity to be 0.71m/s as the marble rolled through the spiral.

Step 5: Eating Breakfast and Leaving for School

For the fifth step of our Rube Goldberg Machine, we had the marble roll out of the spiral onto another ramp. The marble would roll on the ramp and pass a cardboard piece with a hand-drawn Rice Krispies Cereal title on it to show eating breakfast. After, the marble continues to roll past the cardboard and it hits a mini toy car. The car is held in place with a wedge, large enough so that it doesn't roll down the ramp early, but just small enough for the car to roll over it when hit with the marble. The marble and the car both roll down the ramp together all the way to the other side of the board. It is the longest ramp in our Rube Goldberg Machine with a distance of 0.95m. When the marble rolls past the carboard piece and hits the toy car, there is an elastic collision, which means that all of the kinetic energy that the marble had, is transferred to the car. This gives the car the push to get over the wedge. The marble has 0.089N of force when it hits the 0.033kg car. The car then accelerates at 1.78m/s^2 down the ramp, which has a mechanical advantage of 11.25.

Step 6: Arriving at School

For our next step, the car has just rolled down the ramp, and when it gets within a few inches of the end, it is stopped by another wedge, The wedge also has a marble behind it, so when the car hits the wedge, the marble can go around and continue on. The marble rolls of the edge of the ramp and falls down onto steps with class names. This shows arriving at school. The new marble weighs 0.0165kg. While it is rolling over the side, the average velocity of its fall is 0.49m/s.

Step 7: Going to Classes

For the seventh step of our Rube Goldberg Machine, the marble has just fallen off the ramp and landed on wooden steps with class names on it. The marble proceeds to roll down the steps, which of there are five and have the following class names on them: Math, Science, English, Spanish, and PE. The marble starts at the top of the steps and has a potential energy of 0.0329J. It then rolls down the steps in 0.7s with a distance of 0.52m. The average velocity is 0.67m/s, and from there we calculated the kinetic energy to be 0.0036J.

Step 8: Eating Dinner

For our eighth step, the marble rolls down the last class step and falls onto another ramp, but it is in the shape of a hot dog, and has a drawing of a hot dog on it. The marble rolls down this ramp, which is quite steep and falls into a cup. This represents eating dinner towards the end of the day. The marble rolls down the 0.13m ramp in about 0.19s for aan average velocity of 0.34m/s. From there, we calculated the acceleration to be 1.79m/s^2.

Step 9: Getting Ready for Bed

Our second to last step of our machine is the marble rolls off of the ramp into a plastic cup that is being supported by leaning on the side of the hot dog ramp and with a screw in the opposite corner. The screw helps keep the cup up for long enough, but when the marble rolls into it, the cup will give way to the screw and fall. The cup is attached to a rope which is connected to the bed sheets via pulley. The marble falling into the cup represents getting ready for bed because it isn't at the very end of the day, but it is close. The cup falls down 0.16m to the ground when the marble falls into it, and that triggers the pulley.

Step 10: Going to Bed

Our final step of our Rube Goldberg Machine is a pulley system. When the plastic cup falls down, the rope is pulled through a pulley. The other side of the rope is connected to folded over bed sheets. When the rope is pulled through the pulley, it pulls the bed sheets over, thus our final step of going to bed. The mechanical advantage of our pulley is 1 because there is only one pulley. Thus, the bed sheets are pulled over, and our Rube Goldberg Machine has run its full course.

Equations we Used in our Rube Goldberg Machine

While doing the calculations for our Rube Goldberg Machine, we had to use the following equations to find our solutions:

• Acceleration=change in velocity/change in time
• Velocity=change in distance/change in time
• Potential Energy=Kinetic Energy
• Potential Energy=mass*acceleration due to gravity (9.8m/s^2)*height
• Kinetic Energy=1/2 mass*velocity^2
• Force=mass*acceleration
• Work=Force*distance
• Vertical Distance (height)=1/2 acceleration due to gravity (9.8m/s^2)*time of fall^2
• Horizontal Distance=1/2 acceleration*time^2
• Ideal Mechanical Advantage=distance effort/distance load
• Mechanical Advantage of Pulleys=# of pulleys

Physics Concepts

Acceleration

Acceleration (a) is used to find how fast an object is speeding up or slowing down; the rate of change of velocity. The equation for acceleration is acceleration (a)= velocity (v)/time (t). To find the acceleration, you first need to find the objects velocity. Your velocity should have the unit meters per second (m/s). Once you have found the velocity, you will need to find the time. To find time of a free falling object, you can use the distance vertical equation, as long as you know the height. Otherwise, you can time it, like you would do for horizontal distance. Once you have your time in seconds (s), then you divide. To calculate acceleration, take your velocity and divide that by your time. (a=[m/s]/[s]). Your final answer will be a number and then your units will end up as meters per second times second (m/s^2).

Velocity

Velocity (v) is the rate of covered distance in a specific direction, also referred to as speed in a specific direction. The equation for velocity is velocity (v)=distance (d)/time (t). To find velocity, you first means to measure the distance being traveled. Make sure to put your units in meters (m). Once you have the distance, the next step is to find the time in seconds (s). Once you have both the distance and the time, you will divide the distance by your time (v=[m]/[s]). Your final answer will be a number and then your units should be meters per second (m/s).

Time

Time (t) is the progress and sequence of events. We more commonly use time to figure out when something is or how long something has been going on for. In Physics, time is used in many different equations, such as acceleration, velocity, and distance. Finding the time can be tricky sometimes, especially if you don't have a stopwatch. If you do have a stopwatch, you can easily time something to figure out how long an object has been doing something. Without a stopwatch, another way to find time is by the vertical distance (height) equation, but you first have to know the height from which it is falling. Once you have found the time, convert to seconds if not already, and it can easily be plugged into any equation that requires the time.

Horizontal Distance

Horizontal Distance (d) or (d[subscript]h) is the amount of space between two points. The equation for horizontal distance is distance (d)=1/2 acceleration (a)*time (t)^2. Distance can also be measured with other tools, such as rulers, meter sticks, or tape measures. While you can measure distance in units like centimeters (cm), most equations involving distance are easier to solve using the unit meters (m). Once you have the distance that is required, convert the units to meters and plug it into the equation.

Vertical Distance (height)

Vertical Distance (d[subscript]v) or height (h) is the distance an object is falling from or the vertical distance between two points. The equation for vertical distance is vertical distance (d[subscript]v)=1/2 acceleration due to gravity (a[subscript]g)*time of fall (t[subscript]fall)^2. This equation can not only be used to find height, but also the time an object has been falling. Once you have the height of a space, you can plug it in to equations like potential energy.

Acceleration due to Gravity

Acceleration due to gravity (a[subscript]g) is the acceleration an object has while free falling. The acceleration due to gravity is always going to be 9.8 meters per second squared (9.8m/s^2). Acceleration due to gravity is useful when doing equations like vertical distance.

Potential Energy

Potential Energy (PE) is the amount of energy it has due to its height. The equation for potential energy is potential energy (PE)=mass (m)*acceleration due to gravity (a[subscript]g)*height (h). It is useful for finding what the potential energy and object has before it rolls down another object or before it free falls.

Kinetic Energy

Kinetic Energy (KE) is the amount of energy an object has after it has fallen or moved. The equation for kinetic energy is kinetic energy (KE)=1/2 mass (m)*velocity (v)^2. Kinetic energy is used to find how much energy an object has after it has moved. In a world without friction or air resistance, all of the potential energy (PE) changes into kinetic energy (KE). But since our world does have air resistance and friction, kinetic energy will always be less than potential energy.

Mass

The mass (m) of an object is the amount of matter an object holds. There is no specific equation for mass, but it is usually measured in grams (g) or kilograms (kg). Mass is used to plug into equations like potential energy (PE) and kinetic energy (KE).

Force

Force (F) is the push or pull on an object. The equation for force is force (F)=mass (m)*acceleration (a). The unit for force is Newtons (N). Force is used to see how much weight and object has while in motion or at rest. Force can also be used to find the work (W) of an object, but only if it is in motion.

Work

Work (W) is the amount of energy put into something. The equation for work is work (W)=force (F)*distance (d). The unit for work is Joules (J). There is only work if something is in motion. If there is no motion, then there is no work.

Joules

Joules (J) is the unit used for equations like work (W). Joules is another way of saying kilograms (kg)*meters (m)/seconds^2 (s^2) or newton (N)*meters (m).

Newtons

Newtons (N) is the unit for force (F). It is the unit for how much push or pull is on an object.

Ideal Mechanical Advantage

Ideal Mechanical Advantage (MA[subscript]ideal) is how much further you have to push due to using a tool or object. The equation for ideal mechanical advantage is ideal mechanical advantage (MA[subscript]ideal)=distance (d) effort/distance (d) load. You use ideal mechanical advantage to find how much more distance something can move because of the efficiency.

Real Mechanical Advantage

Real Mechanical Advantage (MA[subscript]real) is how much easier a tool or object makes a task. The equation for real mechanical advantage is real mechanical advantage (MA[subscript]real)=force (F) load/force (F) effort. Real mechanical advantage is how efficient a tool or object actually is. Both real mechanical advantage and ideal mechanical advantage have no units, just the number.

Effort

Effort, like used in real mechanical advantage (MA[subscript]real) and ideal mechanical advantage (MA[subscript]ideal) is saying that is where the human or whoever is doing the work is putting their effort into.

Load

Load like used in real mechanical advantage (MA[subscript]real) and ideal mechanical advantage (MA[subscript]ideal) is saying that is where the weight is, or where the effort is going to.

Elements of Design, Energy Transfers and Simple Machines

The 3 Elements of Design

Contrast

The first element of design in our Rube Goldberg Machine is contrast. To show this, we painted the board white and the ramps purple. We didn't want to have the whole board and the ramps all be wood colored or all one color, so we chose two colors, one making the other pop out. We think the white did this well and make the purple ramps stand out among everything else.

Balance

We made our 10 steps in a zigzag pattern so that the machine wasn't one diagonal piece that left everywhere else blank. We chose to have our machine wind back and forth and have some parts stick out to create the balanced effect and to make our project more visually appealing.

Movement

Some Rube Goldberg Machines had theirs go by in an instant, so fast to where you could hardly see the separate steps. Most of the other machines took around 6 or 7 seconds to run, but our took 14, making it at least twice as long as some of the others. We made the marbles and cars move slower by having more gradual ramps that helped keep the speed low.

The 4 Energy Transfers

Lever-Step 2

In Step 2, the kinetic energy of our heavy weighted marble combined with the mechanical advantage of our level made the side of our lever with the hand go up with more kinetic energy. This is the first energy transfer in our Rube Goldberg Machine, the energy transferring from one side of the lever to the other.

Marble-Step 3

In Step 3, the marble is sitting on top of a few weighted rings. Before it rolls down the ramp, it has potential energy. Once it has rolled down, the energy is kinetic. This is another energy transfer-potential to kinetic.

Marble-Step 7

In Step 7, there is another potential to kinetic energy transfer. The marble is sitting on the edge of the long ramp, held back from falling by a wedge. When the car hits it, its potential energy is transformed into kinetic as it falls over the side.

Step 10-Pulley

In Step 10, there is an energy transfer having to do with the pulley. When the marble rolls into the cup, its kinetic energy makes the cup fall down, making the rope pulled, and then the bed sheets are pulled over as a result.

The 5 Simple Machines

Ramp

The first type of simple machine in our Rube Goldberg Machine is a ramp. We have quite a few of those throughout the process and each one is another simple machine. Ramps are "decline planes" which means that whatever is on the ramp and moving downward like a car or marble, the ramp slows down the acceleration by making the distance of height reduction over a larger space instead of the object free falling.

Lever

Levers are simple machines because the fulcrum is closer to one side of the lever than the other. So when the shorter side is pushed down, the larger side moves over a larger space. We have two levers in Steps 2 and 3, where one hits the other and makes it go the opposite direction.

Screw/Spiral

Screws/Spirals are simple machines because they slow the marbles or whatever is inside/on top of them down by making it do slower gradual circles and extending the distance. We have one of these in Step 4, where the marble rolls into a hole, goes down the spiral, and continues on at a slower pace than it would if it had been free falling.

Wedge

Wedges are simple machines because they hold things in place with their triangular shape. In Step 5, it holds the car in place and keeps it from going down the ramp until it is hit by the marble. In Step 6, the other marble is held from going over the edge until the car hits it, similar to the wedge in Step 5.

Pulley

Pulleys are simple machines because they changes the direction of force and they make it easier to lift certain objects. They also cause energy transfers because the energy goes from one side of the pulley to the other. In Steps 9 and 10 the marble falls into the cup, and the force of the fall in changed to the other side to lift the bed sheet covers.

Construction Log

Day 1-Developed theme and discussed steps for project

Day 2-Started blueprint

Day 3-Finished blueprint

Day 4-Painted board white and found necessary supplies (ramps, marbles, PVC pipe, and cups)

Day 5-Constructed first ramp and measured dimensions for lever

Day 6-Drilled lever to board and started constructing second lever

Day 7-Finished second lever and screw

Day 8-Drilled ramps to board, made and put wedges in place

Day 9-Added ramps and painted them all purple

Day 10-Drilled wooden blocks and cut wood for hot dog

Day 11-Drilled on hot dog, made and drilled on bed, and constructed pulley

Day 12-Found energy transfers, elements of design, and simple machines

Day 13-Made decorations and started calculations

Day 14-Finished calculations, made construction log and started final blueprint

Day 15-Finished final blueprint and started preparing for presentation

Day 16-Practiced presentation multiple times

Reflection

For our first project of the year and of STEM Marin, I think it went very well, and my group and I are proud of our final product. In our group, I feel like everyone participated and contributed pretty equally, as it was not one person doing all of the work. I also feel like there is room for improvement. One thing that we could have done better is dividing and conquering during our building time. While we finished on time, it was very rushed because we were moving slowly and we all were working on the same thing at the same time instead of starting new things to get them done sooner. Another skill we could improve on is communication between all group members and making sure everyone know what is happening. There were a few times where one person would be building something, but then others decide to change it in a large or small way. It would then confuse others when we weren't exactly sure what was happening, and more communication could help with that.

On the other hand, some things that I think went really well were our collaboration/cooperation and our productivity. When we were working together, we made sure that we worked well and efficiently with each other and we also made sure that we incorporated and listened to everyone's ideas and thoughts. One way we did this is while we were planning out our Rube Goldberg Machine. We made sure that after jotting down a basic draft, we took pieces from everyone's drafts and made it into one big blueprint to incorporate everyone's ideas. We also worked as quickly as we could, but being careful to make sure that everything was done correctly. Our productivity was also one of our strengths. For example, we could all be working on the ramps, but doing different jobs such as cutting and chiseling the ramps, planning out where it should go and getting needed materials, and finding objects like marbles and cars to run along them. Being productive like this helped us get things done and stay mostly on time with where we should have been.

There were many ups and downs, good and bads, and strengths and weaknesses to our project, but overall our Rube Goldberg Machine was very successful, and it has helped me to learn new skills that I can use in other projects and throughout my high school career.