For this project, we had to pick a time and a place in the past to design our trebuchet model after. For our time and location, we decided on San Francisco in 2003. My group's original idea was San Francisco in 2023, but that is still in the future and we have no way of researching what it is going to be like. In order to incorporate San Francisco, we decided to use the Golden Gate Bridge which is why the base of our trebuchet is red. We also used yellow because that is one of the color of San Francisco. It was originally supposed to be gold, but the common public disconnected it as yellow. We put a city in the background representing that San Francisco is a big city at night with red writing. My greatest strength in this project was perseverance because at first I didn't really like one of my partners, but as the project progressed I grew to being happy that he was one of my partners.
rube goldberg project
For the first semester of Physics this year, we made Rube Goldbergs. The end goal was to apply a band-aid to something using simple machines. These were pulleys, levers, wedges, wheels and axles, inclined planes, and screws. We used a pulley in one of our steps which was triggered by a tennis ball rolling down a ramp and falling into a bucket, activating the pulley. We included a lever by having dominoes fall and land on the end of it to release a marble. And one of the other simple machines we used was an inclined plane. This was actually part of one of my steps, and we had a marble go down an inclined plane to trigger the dominoes. Our Rube Goldberg included momentum in the second step. A marble would roll down a ramp and start basically the entire project. I also used inertia in my step because when the marble rolled down the ramp, it had to be lined up with the dominoes so that it hit them, making the other steps work. I had a lot of trouble getting the ball to roll to the perfect stop, but eventually I got it. We used kinetic energy when a hollow golf ball was hit by a marble, so the marble would be putting its energy into the golf ball. That golf ball then put its energy into a tennis ball in the next step. We had to answer two equations about potential and kinetic energy. We had to calculate the potential energy of a steel ball of 7.0 grams that 50 centimeters into a bucket, that then triggers a pulley. We had to find PE=mgh, PE being potential energy and mhg being mass (which is kilograms), gravity (9.81m/s squared), and height (meters). We had to convert grams into kilograms, so I used the equation PE=mgh, and divided by 1,000, getting 0.007. You also have to divide 50 by 100, giving us .5. You keep the same force of gravity, which is 9.81, so the ending equation should be 0.007 x .5 x 9.81. When you finish this problem the answer is 0.0343 joules. The second problem was about kinetic energy. A steel ball landed in a bucket that has a velocity of 45 centimeters per second, and we were asked to find the kinetic energy of the ball. When I was doing the equation for this, I used 0.007 from the potential energy equation. I also then divided 45 by 100 to get 0.45. My final equation was 0.007 x ½ x 0.45 which equaled 0.0007085 joules.
The first thing we did in this project was make prototype rubes. They were small and only had to include three of the simple machines. After we did that, we got into our project groups and started sketching out steps for the actual project. We made two sketches of our project, then started building. We were pretty lucky, because when we drew out our personal steps we found that they all fit together. For me, my strongest 21st Century Skill (collaboration, critical thinking, communication, and critical thinking) during this project was communication because I personally like to control everything. So, I had to sit back and let other people take over for once, which was hard, but I think it really benefited our group. I think that the skill I grew most in is collaboration because I feel like I do much better on projects that I work alone on because I can do whatever I want. So during this project I really had to listen to other people’s ideas and what they had to say, and I actually really enjoyed it.