Laura Devilbiss

Laura DeVilbiss Brannon Dickerson Leo Khmelniker PHYS 151 Section C1 4/26/06

Music to Your Ears Table of Contents

Music to Your Ears...... I Table of Contents...... II Executive summary...... II Design process...... II Description of device...... III Detailed analysis...... IV Conclusion...... V Technical appendix...... V Bill of Materials...... V Calculations...... V Measurements...... V First Energy Transfer...... VI Second Energy Transfer...... VI Third Energy Transfer...... VI Fourth Energy Transfer...... VII Contributions...... VII Leo...... VII Brannon...... VII Laura...... VII

Executive summary

We have built a Rube-Goldberg device that performs the simple task of turning on an iPod through a series of distinct steps. Each step works by utilizing simple energy conversions of kinetic and potential energies.

Design process

As a group, we first decided that we wanted to design a device that would make a call on cell phone. Initially, the energy conversion steps we designed worked, but we

II couldn’t come up with a reliable way to actually press the button on the phone because it was so small. Then, we came up with the idea to have an iPod play music through a dock with speakers as the end result.

Once we decided on the task to perform, we arranged our original energy conversion steps into a more efficient series. With a rough draft of our design, we had to match the given criteria: we incorporated four conversions of energy (Calculations) and we used materials that came to a maximum total of $25 (Bill of Materials). We had to construct a hump made of duct to set the car on so that it wouldn’t start to roll down the hill on its own. Also, we had to place bumpers on the inside of the tube at the bottom of the hill so that the car hid hit the right spot on the iPod.

Construction of device 1

Description of device

“Music to your ears” is made up of dominos, a marble, a funnel, a toy car, a track, an iPod, and iPod dock (Bill of Materials).

III A marble is dropped into a funnel and when it comes out, hits the first domino in a series. The first domino falls, knocking over the rest until the last one hits a car. The car then rolls down a hill constructed of tubing and pushes the play button on the iPod at the bottom.

Device 1

Detailed analysis

To start the process, we drop a marble with potential energy into a funnel and it spins around until it comes out the bottom onto a track as kinetic energy. The marble falls down with kinetic energy until it collides with the first domino that has potential energy.

A series of dominos with potential energy is set into motion when the marble pushes the first domino, causing it to fall into the next domino. Each preceding domino knocks over the next until the last in the series falls down as kinetic energy. The last domino that falls pushes the car, which is sitting at the top of a hill. The transfer of kinetic energy pushes the car with potential energy over the edge of the hill. Finally, the car rolls down the hill

IV until it reaches the bottom where the kinetic energy is used to push the button on the iPod

and music is played.

Conclusion

I think that our device was very successful. Our first demonstration in class didn’t

work because our dominoes weren’t lined up straight. After we corrected the problem,

our demonstration went very well. We all learned how to work better as a team and how

to manage as well as allocating tasks. The only problems we had were design and

construction flaws that were easily fixed by trial and error.

Technical appendix

Bill of Materials

Item Price Dominos $6.95 Tube $9.99 Car $0.89 Everything else Already owned – free Total $17.83

Calculations

Measurements 0.005 kg Mass of marble Mass of domino 0.016 kg

Mass of car 0.056 kg

V Change in height: marble to domino 0.00127 m

Change in height: domino 0.00508 m

Change in height: car to iPod 0.03048 m

First Energy Transfer

PEm  KEm 2 mghm  1/ 2mv'm 2 (0.005kg *9.81m / s *0.00127m)  1/ 2*(0.005kg)v'm

v'm  0.15785m / s 5 PEm  6.229*10 J 5 KEm  6.229*10 J

Second Energy Transfer

KEm  PEd  KEd1 2 KEm  mghd1  1/ 2mv'd1 5 2 (6.229*10 J)  (0.016kg *9.81m / s *0.00508m)  1/ 2*(0.016kg)v'd1

v'd1  0.31574m / s 4 KEd1  7.975*10 J

Third Energy Transfer

KEd1  PEd 6  KEd 6 2 KEd1  mghd 6  1/ 2mv'd 6 4 2 7.975J *10 J  (0.016kg *9.81m / s *0.00508m)  1/ 2*(0.016kg)v'd 6

v'd 6  0.4464m / s

KEd 6  0.001595J

Fourth Energy Transfer

KEd 6  PEc  KEc 2 KEd 6  mghc  1/ 2mv'c 2 0.001595J  (0.056kg *9.81m / s *0.03048m)  1/ 2*(0.056kg)v'c

v'c  0.7733m / s

KEc  0.02165J

VI  In all of the calculations, we assumed negligible air resistance and friction forces.

Contributions

 Design

 Construction

 Power point

Brannon

 Design

 Construction

 Materials

 Design

 Report

 Calculations

VII VIII