The Magic School Bus. December 1, Andy Phillips Shannon Kelly Matt Stout Raymond Poon. Team Number 7 EF C2

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1 The Magic School Bus December 1, 009 Andy Phillips Shannon Kelly Matt Stout Raymond Poon Team Number 7 EF C 1 Page

2 Objective The objective of our project was to build a Rube Goldberg device that would display a banner of The University of Tennessee by using multiple properties of physics. Rube Goldberg machines came from an American cartoonist, engineer and inventor, Reuben Lucius Luc Goldberg. He was most commonly recognized for a popular series of cartoons he created that showed complex devices that performed simple tasks in indirect and complicated ways. For our project, this his device had to include at least four concepts we went over over in EF 151 this semester and it had to go through at least five steps in under two minutes. Description of our device Our project begins with a group pulling out a pin that starts a marble down a track. As the marble goes down the first track, it falls fal off onto the second track that goes in the opposite direction. When the marble goes to the end of the track, it falls into a tube and flies into a funnel. Then it spins around the funnel and goes down the second tube. After the ball falls through the funnel, it falls through a series of tubes and lands onto a mousetrap. This mousetrap then pulls a string which is attached ed to the nail. As A the mousetrap snaps, it pulls the string downwards which causes the nail to fall. Above the nail there is a bus which hich starts to roll as the nail is pulled from underneath. After the bus rolls Page

3 off the track, it falls into a bucket and falls to the ground. The bucket is also connected to a pulley, so as the car s weight pushes the bucket downward, the other side of the pullet raises our flag. To set off the group behind us, we used a mouse trap which pulled a string that was connected to their device. The mouse trap would trigger when the car fell into the bucket and fell to the ground, landing on it. Description of Design Process First we looked at our sketch and realized that it was too problematical and difficult to accomplish, so we restarted and brain stormed. We determined that it was a smarter idea to make a simpler device that worked one hundred percent of the time rather than a complex device that only worked fifty to seventy five percent of the time. Then we decided on the current plan. During the process, we cut the wood into dimensions so that we could start at the highest point. As we began to construct, we decided to work step by step making sure it worked and corrected it if it failed before we moved on the next step using trial and error. As we were building, we constructed the design to start from the highest point of the device. It started with linear movement going down the two ramps with the marble and going through the first tube. The marble increases its speed as it travels downward through the tube and projects itself into the funnel after the tube ends using projectile motion. The marble spins around in the funnel, increasing its RMP s as the radius decreases, but velocity remains the same even though it looks like it spins faster. In the funnel the marble has angular momentum. The marble travels through the second set of tubes continuing to have linear momentum and then landing on the mouse trap. 3 P a g e

4 The mousetrap has torque which pulls the nail out from the bus and releases it, causing it to start moving down the declined ramp into the bucket. Results of Testing Our results from our presentation went hand in hand with the results from when we tested it. We always managed to either raise our flag or set off the group behind us. We decided early on that it was more important for our machine to work than to be really complex and come with risks our failure. Try 1 Try Try 3 Average Time (sec) Success (100% or 0%) 100% 100% 100% 100% Budget We were given a budget of twenty dollars to create our Rube Goldberg device. We decided to use most materials that we already had from our homes to save the cost of the project. Item Cost Pieces of plywood $ Paint sticks $0.00 Plastic tube $0.00 Piece PCP pipe funnel $0.00 Painter s tape $0.00 Aluminum tape $0.00 Pulleys $1.9 each 4 P a g e

5 Packs of brackets $1.75 each McDonalds cups $0.00 Nails/screws $0.00 Marble $0.5 Mousetrap $1.49 Metal wire $0.00 Funnel $.19 School Bus $1.00 Flag $0.00 Wood sticks $0.00 Chip clip $0.00 String $0.00 Liquid nails $0.00 Total: $11.01 *all costs of $0.00 are because we already had items available 5 P a g e

6 Calculations Find Acceleration of s 1= 0 t=1 sec in s = 3in v 1= 0 find a = 6 sec s = s + v t a t Find the speed of the projectile motion As we looked for the speed of the ball as it is projected, the speed of the ball before it was projected needs to be found. This is found by the Conservation of Energy equation since energy is conserved as it falls through the tube. mgh + mv0 + k x 0 + Win = mghf + mv + k x f + E f After that you would use the projectile motion equation using the angle of jump, and the positions of the ball as it jumps. y y 0 = ( x x0 ) tanθ (1 + tan θ )( x x 0 ) v0 for v, using 10 degrees as the angle, and for the initial x and y would be at (0,0) g As you solve loss 6 P a g e

7 Conclusion Teamwork was a key factor in getting this project done right and on time. Each group member had to contribute a little of their the time, effort, and knowledge to the team if we were to get things done efficiently. Thankfully we never had a problem with one person not being there on time or showing up. Everyone veryone contributed in our group which made things fun compared to frustrating if you were the only one working. working We learned that in engineering a lot of the project consists of trial and error and you must learn from your mistakes. If one design didn t work, we would correct it and attempt it another time. References We used notes and equations provided to us from lectures lectures.. We also worked together and combined all our knowledge to create this paper. 7 Page