Team: Troy P. and Mike G.

Our Purpose / Goal:
With our simple machine(s) we are trying to perform the simple task of hitting play on an ipod through various transfers of energy. The otherwise strenuous and finesse task of pushing a button is made as simple as dropping a ball, allowing you to save some energy and enjoy your music with your friends, family, and goblin!

Description of Machine:
Our model begins with a series of ramps (not a big truck) on which a wooden ball rolls until it finally descends onto a trail of dominoes. The ball hitting the dominoes creates a chain reaction of falling dominoes that runs into the back of a hot wheel car teetering perfectly on the edge of the a ramp with a string attached to it. When the last domino falls, the car is sent racing off the ramp, towards the ground. The tension created by the car pulling on the string is used to pull out a pin in a rock tied to more string. This pin releases a bat attached to an axis allowing it to swing. The bat swings hitting a billiard ball which is resting on a track leading to an ipod with an apparatus made from a CD and a Ticonderoga pencil eraser which allows the play button to be pressed with the collision of the ball. The iPod is connected to an amplifier and when play is pressed we will be able to hear fantastic music play.

Theoretical Background:
Throughout our Rube Goldberg Machine, there are a few transfers of motion and energy, most of them kinetic and potential energy. The Fun starts with the drop of a wooden ball onto a ramp and it starts rolling down multiple ramps, this converts the ball's potential energy into horizontal kinetic energy. When the ball gets to the bottom of the ramps, it transfers its kinetic energy to the dominoes, and each dominoes transfers kinetic energy to the next one until it gets to the car. The car is knocked down onto a ramp using its potential energy / gravity to pull the string attached to it. The tension on the string pulls the pin out (kinetic energy) and the pin releases a lifted up bat (potential energy -> kinetic) to swing down and hit a ball like a pendulum (kinetic -> kinetic). The ball rolls down the track and hits the iPod, pressing the play button(more kinetics). The play button completes an electronic circuit inside the iPod, in turn completing and ending a series of electrical circuits (each adding a little energy as it goes from the battery of the iPod) eventually making it send electrical pulses down a cable leading to the amp. The amp then adds a load of electricity (from the wall) to the magnets inside the speaker which makes magnetism move the speaker to vibrate and give us the great sound of what we want to hear. To measure the Potential energy forces, we could simply weigh the objects and the height they fall, for kinetics, we can see how much they weigh and how fast they are moving. For the electronic parts however, you would have to use something like a battery tester on the audio cable coming from the iPod. However, for the amp, you would probably fry any kind of battery tester, but you would probably have to measure the power output from the wall somehow.

Data Section:

  • The original idea was to have the amp rattle salt into a beaker of distilled water, making electricity flow through wires already in the beaker, but for some reason the water wouldn't conduct the electricity correctly so we scraped the whole electricity idea and worked backwards from the amp starting.
  • We first made bat swing on string, but the string brought too much tension on the sides of the card board box so we made the bat swing on a drumstick.
  • We started making the ramps for the ball to roll down with only nails under them for support, we quickly realized that we needed more to keep them in place so we utilized tape.
  • The first ball we used was a rubber bouncy ball the size of a golf ball, however this was way too heavy and knocked our ramps down on impact, we then substituted that with a paint ball. The ball however was too small and rivets in the ramps made it bounce out. Finally we needed a non bouncy, light weight ball. We found our winning wooden ball around the size of a cherry tomato
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  • For this ball however, it rolled too fast, and rolled over the ramps. To fix this we had to lower the slope of the ramps and make them even and more spread out (more track to roll uphill)
  • Last minute at school we had noticed that the falling car wasn't enough to pull the pin for the bat with the full tension of the loaded bat. To quick fix this we added a domino (taped it) to the car.
  • However this presented another problem, the car was now too heavy for the dominoes to knock it down the ramp. We experimented with the placement of the car, and if we got the car barely teetering over the edge of the ramp it would work.


The final assembly of the project at school was overall a success. We had a few things to adjust to once we got there, but we adapted fine. There was one part that took a lot of precision in "arming" the project, and that was getting the car to rest right on the edge of the ramp, so that that the slightest tap would set it in motion. We got it down pretty good to where it was working every time, but for some reason, we set it up wrong the one time that it counted (figures) but it was a slight fault. There was however some wear and tear on the project though. Every time the ball rolled down the ramps and hit the next one, the ramps would kind of shake. With enough trials, some of the ramps nails may get dislodged and flimsy, and have to be resettled in.


In building this machine we were able to further our understanding of energy and energy transfers by creating something that is simple yet intriguing. Our approach was pretty straightforward requiring few complex elements. We started by creating a goal; what our machine would be made to do. After coming up with the idea to start the ipod we though of ways we could hit the button. The ball was our first choice and worked perfectly. We immediately found that it was much easier to work backwards with this project. We thought of what we wanted to happen and then we asked ourselves “How will we make this happen?”. For us, this was the most challenging part.

Some of our ideas were too difficult to create and replicate in the classroom so they had to be discarded. It is important for students to consider what variables can effect their design and try to remain as rational as possible regarding what they can and cannot do. In the end, we had a somewhat impressive machine which we were able to make work perfectly. Unfortunately in our final presentation, to our surprise, the dominoes were not able to push the car off of the desk and it required a nudge by Troy to get it to fall. Other than that little mishap we were able to achieve our goal and fill peoples hearts with the sound of ALRUGO!

oh yeah..

physics is pwnt