Before starting construction of our rube Goldberg machine my group and I researched the simple machines and all the other information we knew we needed to know. After that we spent a while building our Rube Goldberg. We ran into lots of problems and had to change many steps; such as the 1st pulley, the screw, the zip-line and the scissors. On the last week we calculated all the physics problems of our machine such as potential and kinetic energy, mechanical advantage, velocity, force and more!
Potential energy is calculated by mgh (mass times gravity times height), while kinetic energy is calculated by 1/2 mass times velocity squared. We used these calculations for certain incline planes. Velocity is the change in distance over the change in time. We calculated velocity for a ball rolling down an incline plane We also found mechanical advantage by taking the length/height for incline planes and screws and we counted the number of pulleys to find the mechanical advantage of those. We researched toppling which is when the center of gravity comes out of the area of support, we used this for the dominos. Force = ma (mass times acceleration), we used this equation to find the force of the scissors.
Rube Goldberg Steps:
Step one: this was the incline plane which has a Potential Energy=Mass x Gravity x Velocity=0.0066885Joules and a Kinetic Energy= 1/2Mass x Velocity^2=0.0001029 Joules
Step two: this step was a pulley, one side was a bucket and the other was a nail (working a a wedge) in a hole. the mechanical advantage is about one
Step three: in this step a the ball behind the nail is released down an incline plane. The ball rolls down the incline plane with a velocity of 0.62 m/s
Step four: step four is a screw. The mechanical advantage is about 4.5, which means its about 4.5x less force on the ball.
Step five: after the screw the ball knocks into dominos causing the toppling effect
Step six: in this step the domino falls onto a lever attached to a string tied to a platform. The domino with a mass of 0.015kg is enough to knock the lever off balance and the platform slides away
Step seven: step six causes a weight to slide down a zip-line which acts as an incline plane
Step eight: the weight hits the truck at 0.61m/s. The force on the car is 0.61 m/s
Step nine: another energy transfer occurs in step nine when the truck hits a weight which falls off a platform
Step ten: the 300g weight falls, the weight is attached to a pulley when the weight falls the rope in the pulley is pulled closing scissors attached to the other side of the rope
Step eleven: the scissors cut a string attached to a rubber band that has a pencil on it. When the string is cut the scissors are launched.
And that was the end goal of our Rube Goldberg!
I think our group worked well together and we were good at solving problems that came our way such as our first pulley system that did not work for the longest time, yet we still kept working on it and tweaking it each time it didn't work. Our group was good at constructing and engineering new steps such as the scissors that worked nearly every time. We could have communicated a bit clearer when talking about who should do what. I learned that I work better when people give me a job versus just saying to make myself busy. I also learned that I am best when not working under pressure. I could have been better at building steps and doing my own thing and I will work on that more and more!
Potential energy is calculated by mgh (mass times gravity times height), while kinetic energy is calculated by 1/2 mass times velocity squared. We used these calculations for certain incline planes. Velocity is the change in distance over the change in time. We calculated velocity for a ball rolling down an incline plane We also found mechanical advantage by taking the length/height for incline planes and screws and we counted the number of pulleys to find the mechanical advantage of those. We researched toppling which is when the center of gravity comes out of the area of support, we used this for the dominos. Force = ma (mass times acceleration), we used this equation to find the force of the scissors.
Rube Goldberg Steps:
Step one: this was the incline plane which has a Potential Energy=Mass x Gravity x Velocity=0.0066885Joules and a Kinetic Energy= 1/2Mass x Velocity^2=0.0001029 Joules
Step two: this step was a pulley, one side was a bucket and the other was a nail (working a a wedge) in a hole. the mechanical advantage is about one
Step three: in this step a the ball behind the nail is released down an incline plane. The ball rolls down the incline plane with a velocity of 0.62 m/s
Step four: step four is a screw. The mechanical advantage is about 4.5, which means its about 4.5x less force on the ball.
Step five: after the screw the ball knocks into dominos causing the toppling effect
Step six: in this step the domino falls onto a lever attached to a string tied to a platform. The domino with a mass of 0.015kg is enough to knock the lever off balance and the platform slides away
Step seven: step six causes a weight to slide down a zip-line which acts as an incline plane
Step eight: the weight hits the truck at 0.61m/s. The force on the car is 0.61 m/s
Step nine: another energy transfer occurs in step nine when the truck hits a weight which falls off a platform
Step ten: the 300g weight falls, the weight is attached to a pulley when the weight falls the rope in the pulley is pulled closing scissors attached to the other side of the rope
Step eleven: the scissors cut a string attached to a rubber band that has a pencil on it. When the string is cut the scissors are launched.
And that was the end goal of our Rube Goldberg!
I think our group worked well together and we were good at solving problems that came our way such as our first pulley system that did not work for the longest time, yet we still kept working on it and tweaking it each time it didn't work. Our group was good at constructing and engineering new steps such as the scissors that worked nearly every time. We could have communicated a bit clearer when talking about who should do what. I learned that I work better when people give me a job versus just saying to make myself busy. I also learned that I am best when not working under pressure. I could have been better at building steps and doing my own thing and I will work on that more and more!