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Rube Goldberg was a cartoonist born in 1883. His cartoons focused around coming up with convoluted ways of accomplishing simple tasks. Our assignment was to build a real machine similar to the cartoons he has drawn in the past, with a simple task to be accomplished, but a complicated path to get there.
IMG_2260.MOVThe Functioning Board
The Functioning Board
Our machine had a birthday party theme. We showed this with the balloons, cupcakes, present box, "Happy Birthday" banner, and confetti thrower as our final step.
Our assignment for this project was to create a machine, the likes that only Rube Goldberg himself could have imagined, to achieve a simple task of our choosing. We chose to throw confetti into the air as our simple task.
Velocity
Velocity
Velocity is the speed of something in a given direction. That is, the motion of an object by a vector. Speed, however, is the distance moved by an object over time relative to the object itself. Velocity and Speed are both calculated by dividing the change in distance (in meters) by the change in time (in seconds), at which point the velocity or speed will be expressed in meters per second (m/s). In our project, We measured the velocity of our metal ball going down our screw in a downward direction.
Acceleration
Acceleration
Acceleration is the amount something speeds up over time. Most acceleration the occurs in our project is due to gravity, which causes acceleration at approximately 8.9 meters per second squared. However, the use of simple machines such as inclined planes and screws allow that number to be decreased as an object is traversing down the aforementioned simple machine. My group calculated the acceleration of a ball down an inclined plane in step 5, where the acceleration was 2.37m/s^2.
Force
Force
Force is any action on an object that causes a change in motion. Our group calculated the force of a weight falling onto a lever. An object's force is a product of its mass and acceleration. So, with a mass of 0.05 kg and an acceleration due to gravity of 9.8m/s^2, the weight will have a force of 0.49 Newtons
Work
Work
Work is, quite literally, the amount of work done by an object. It is found by multiplying the force of an object by the amount of time the force is applied. Any time an object in the project is moving, it is doing work.
Potential Energy
Potential Energy
Potential energy is the amount of energy expected to be released by an object based on its acceleration, mass, and distance to be traveled by the object. We measured the potential energy of our ball at the top of our machine by first measuring the weight of the ball, then the height of the inclined plane it would be resting on at its highest point, and lastly the acceleration due to gravity (9.8m/s^2). We then multiplied these values together to get a potential energy of 68.69 Joules.
Kinetic Energy
Kinetic Energy
Kinetic energy is the amount of energy released by an object in motion. Theoretically, the kinetic energy of an object is equal to its potential energy, but due to variables like friction and air resistance, it is not so. Kinetic energy can also be found by multiplying half of the mass of an object by its velocity, squared. Any object in the Rube Goldberg machine that is moving has kinetic energy.
Mechanical Advantage
Mechanical Advantage
Mechanical advantage is the number of times easier one of the seven simple machines (lever, inclined plane, screw, wedge, wheel and axle, and pulley). In our project, we used several inclined planes, two wedges, a pulley, a screw, and a lever. The mechanical advantage for our pulley was 1 because all of the energy (minus some negligible friction) was transferred from downward force on one side of the pulley to upward force on the other side of it.
Original Blueprint
Original Blueprint
This is our original blueprint in which we planned to incorporate a wheel and axle component and a wedge component in which a wedge would be pulled out from under a piece of wood, which would then be dropped into a set of levers. Both of these ideas failed in testing. We also wanted our ending task to be a party popper in which the string was pulled at the bottom to shoot confetti into the air. This plan failed when we could not find any place where we could buy an item of that design.
Final Blueprint
Final Blueprint
In these plans, we replaced the wheel and axle with a half-pipe and the complicated wedge system with a simple weight at the edge of a platform, and added a wind-up car held back by a wedge to knock the weight onto the lever below. We also replaced the unavailable popper with some confetti on a platform on the edge of a lever.
Construction Log/ Work Log as Shown in Slideshow
Day 1: We finished our blueprint and started drawing out (on the board) where each piece would go.
Day 2: We began to brainstorm how all the pieces would work together in order to pull the popper and what we would need to do so.
Day 3: We began to build our first inclined plane using a 20 inch piece of wood with a screw on the top attached to a guitar string to go in the pulley and attach to the box. We put a screw through the board and through a straw and hot-glued the wood to the straw so the wood could go from a flat surface to an inclined plane.
Day 4: We started thinking about how we could build our screw. We tried a variety of ways and had a hard time finding the right one. One of the things we tried was twisting a hose around a wooden stick but the hose wasn’t bendy enough to twist perfectly around the stick. We then decided to try hot-gluing cardboard steps onto the stick in a downwards, circular form and then put tape on where the cracks and places the ball would fall out.
Day 5: We attached our lower inclined planes to the board and then drilled a screw up start of the inclined plane to hold the screw in place. We also attached our levers using the same tactic as the beginning inclined plane.
Day 6: We attached the wheel and axle to the board and added a cardboard basket into the wheel to hold the ball in. We then added two screws for a board to rest on and hold up our wedge and heavy block of wood.
Day 7: We soon came to the realization that the wheel and axle and wedge were not going to work out the way we had pictured. We then took that whole part out of our board and began to design new and well functioning steps. We decided that if we added a half-pipe for the ball to gain slightly more force. We then thought of the idea to add a pull back car held back by a small wedge so that when the marble hits the car, the energy would transfer to the car and push past the wedge and then push a weight off of the piece of wood everything is resting on.
Day 8: We added finishing touches to our final blueprint and continued making sure everything was working correctly. We also began making our presentation. We finished our theme, 10 steps, five simple machines, and our schematics/final blueprint pages
Day 9: We added some decorations and made sure all of our steps worked properly worked and added some painting to make our machine more visually appealing. We also started to work on our calculations.
Day 10: We added some finishing touches to the board and practiced our presentation.
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