Rube Goldberg Machine
Analysis of project
For the past month, my group and I have been working on our Rube Goldberg project. I had Mikey, Sally, and Jacob in my group. We have had about 20 hours of build time(plus a couple of lunches) and about 3 days for preparing for our presentation. It has been an exciting and informative past 4 weeks.
Our Rube Goldberg machine has ten total steps. For step one, we have our pulley . We pull the string down and the gate lifts up, letting the car roll down the inclined plane. For step two, we have our car roll down the inclined plane and collide into the ball bearing. For step three, we have our screw. After the ball bearing gets hit by the car, it rolls down our spiral tube. For step four, we have our pegs. The ball bearing comes out of the tube, hits a wall, and goes down our three pegs. For step five, we have our lever. The ball bearing rolls down the pegs and goes down a tube that leads it to the lever. The ball bearing comes out of the tube and hits the lever letting itself and the blue marble (which is on the other side of the lever) down onto the ramp. For step six, we have our ball trap. The ball bearing rolls down the ramp first and goes into a hole in the ramp. Then the blue marble falls off the lever and rolls right over it. For step seven, we have our collision. After the blue marble rolls down the ramp, it drops off it and hits a curve which speeds up the blue marble to hit the clear ball. For step eight, we have our wedge. The clear ball rolls down the ramp it was on and drops into a cup which pulls the wedge out from under the yellow marble. For step nine, we have our ramp/energy transfer. The yellow marble drops down a pipe and hits our golf ball down the ramp. For step ten(our final step), we have our oreo drop. The golf ball rolls down the ramp and hits the oreo, dropping it into the bowl of milk.
We did have some difficulties in the building process. One was getting the lever to work. The blue marble kept catching up to the ball bearing, decelerating the blue marble so much that it couldn't roll over the ball bearing. We were able to fix this by changing the angle of the inclined plane and making the ball trap hole deeper and deeper until the ball bearing made the inclined plane almost flat. We also had trouble with the wedge. The wedge would either start too early or not activate when it was supposed to. It took a while but after changing the angle of the piece of wood that was holding the wedge in place, we figured out a way to make it work most of the time. We also had to mount our board at a 80 degree angle to make sure the ball would go into the right spots every time and to make sure the ball would not fall off the board.
Our Rube Goldberg machine has ten total steps. For step one, we have our pulley . We pull the string down and the gate lifts up, letting the car roll down the inclined plane. For step two, we have our car roll down the inclined plane and collide into the ball bearing. For step three, we have our screw. After the ball bearing gets hit by the car, it rolls down our spiral tube. For step four, we have our pegs. The ball bearing comes out of the tube, hits a wall, and goes down our three pegs. For step five, we have our lever. The ball bearing rolls down the pegs and goes down a tube that leads it to the lever. The ball bearing comes out of the tube and hits the lever letting itself and the blue marble (which is on the other side of the lever) down onto the ramp. For step six, we have our ball trap. The ball bearing rolls down the ramp first and goes into a hole in the ramp. Then the blue marble falls off the lever and rolls right over it. For step seven, we have our collision. After the blue marble rolls down the ramp, it drops off it and hits a curve which speeds up the blue marble to hit the clear ball. For step eight, we have our wedge. The clear ball rolls down the ramp it was on and drops into a cup which pulls the wedge out from under the yellow marble. For step nine, we have our ramp/energy transfer. The yellow marble drops down a pipe and hits our golf ball down the ramp. For step ten(our final step), we have our oreo drop. The golf ball rolls down the ramp and hits the oreo, dropping it into the bowl of milk.
We did have some difficulties in the building process. One was getting the lever to work. The blue marble kept catching up to the ball bearing, decelerating the blue marble so much that it couldn't roll over the ball bearing. We were able to fix this by changing the angle of the inclined plane and making the ball trap hole deeper and deeper until the ball bearing made the inclined plane almost flat. We also had trouble with the wedge. The wedge would either start too early or not activate when it was supposed to. It took a while but after changing the angle of the piece of wood that was holding the wedge in place, we figured out a way to make it work most of the time. We also had to mount our board at a 80 degree angle to make sure the ball would go into the right spots every time and to make sure the ball would not fall off the board.
Concepts
Mechanical Advantage(MA)-it is the measure of the force amplification achieved by using a tool, mechanical device or machine system. You are able to calculate ideal MA and real MA. The formula for ideal MA is distance input over distance output and the formula for real MA is output force over input force. We calculated the MA of our pulley(step 1) and pegs(step 4). The pulleys MA is 1 and the pegs average MA is 2.625.
Force-push or pull on an object. The formula for force is F=ma. We were able to calculate that the force of the ball bearing on the lever(which is 0.13622 N) and the force of the blue marble when its about to hit the clear ball(which is .02 N).
Speed-the magnitude of its velocity. Its formula is speed=d/t. We were able to calculate that the speed of the car in step 2 is .21875 m/s.
Potential Energy(PE)/Kinetic Energy(KE)-PE is the energy stored in an object due to its position and KE is the energy that it possesses due to its motion. The change in PE= the change in KE. There formulas are PE=mgh and KE=1/2mv^2. My group and I were able to calculate that the change in PE for our wedge was .0057 kg/m/s^2(for the yellow marble) and that the KE of the oreo dropping is .0172872 J.
Momentum/Impulse-momentum is force or speed of movement and impulse is a driving or motivating force. Momentum=Impulse. On our screw we calculated the impulse and for our yellow marble hitting the golf ball, we calculated the yellow marbles momentum. The impulse of the screw was .0012 kg/m/s and the momentum of the yellow marble is .0756 kg/m/s.
Deceleration-to decrease the velocity of. We were able to figure out that the blue marble decelerates 57% after it roles over the ball bearing(in the ball trap).
Force-push or pull on an object. The formula for force is F=ma. We were able to calculate that the force of the ball bearing on the lever(which is 0.13622 N) and the force of the blue marble when its about to hit the clear ball(which is .02 N).
Speed-the magnitude of its velocity. Its formula is speed=d/t. We were able to calculate that the speed of the car in step 2 is .21875 m/s.
Potential Energy(PE)/Kinetic Energy(KE)-PE is the energy stored in an object due to its position and KE is the energy that it possesses due to its motion. The change in PE= the change in KE. There formulas are PE=mgh and KE=1/2mv^2. My group and I were able to calculate that the change in PE for our wedge was .0057 kg/m/s^2(for the yellow marble) and that the KE of the oreo dropping is .0172872 J.
Momentum/Impulse-momentum is force or speed of movement and impulse is a driving or motivating force. Momentum=Impulse. On our screw we calculated the impulse and for our yellow marble hitting the golf ball, we calculated the yellow marbles momentum. The impulse of the screw was .0012 kg/m/s and the momentum of the yellow marble is .0756 kg/m/s.
Deceleration-to decrease the velocity of. We were able to figure out that the blue marble decelerates 57% after it roles over the ball bearing(in the ball trap).
Reflection
During this project I was able to learn a lot of new things. Some examples: learning how to use power tools and how to work cooperatively in a group. My group and I also learned that is was hard to work when all of us were trying to work on the same step at the same time. It was difficult when we were all crowded around at one point trying to put everything in at one time. We figured out that splitting into two groups of two helped solve this problem. We also could have improved on our time management. We finished building a couple of days after we were supposed to and had barely any time to make our presentation. In the end though we were able to make it just in time for our presentation night, but it wasn't until the last minute. Another thing we could have improved on was our communication. Sometimes we would have three people working on one part and think the 4th person was working on the next step, when we never even discussed what we were doing for the next step. Communication was sometimes tricky but it all worked out in the end. We did have some peaks and pits during the project. We hit most of our peaks in the end in my opinion because that was when all of the pieces started to come together. We were also communicating a lot better at the end. We were starting to finish our project when other groups were still working on theirs. At the end, it seemed like we had one of the more consistently working projects in the class, and we were coming up with really good ideas. Our pits were probably during the middle of our project. The steps in the middle of the project were never working consistently and it was causing some frustration. Communication wasn't the best during the middle of our project because we all kept wanting to try only our ideas. In all though we were able to come together in the end and finish it all in time while communicating and sharing our ideas. It was a very fun and informative project.