Mesmerizing Vinyl DisplayOliver SheridanAward: Top 100
School: saint xavier high school The picture above captures a vinyl record spinning with a miniature skateboard placed on top of it just before the record was stopped. There are multiple principles of physics at play here, the first of which being rotational motion. The vinyl record was spinning at a constant angular velocity of 3.49 radians per second which I converted from 33 and 1/3 rotations per minute. Additionally, the rotational inertia of the record itself is 0.027432 kg*m^2, assuming the vinyl record would act as a disk or cylinder and calculating with a radius of 12 inches and a mass of 180 grams. The mini skateboard introduces the idea of static friction as the coefficient of friction was high enough to keep the skateboard from moving relative to the record. This also introduces the idea of circular motion as one could use the mass, distance from the center of the record, and velocity of the skateboard to determine the acceleration and force which the tech deck is exerting. Once I turned the record player off, the record took a time of 2.02 seconds to stop spinning, which gives us an angular acceleration of -1.7277 radians per second squared. Finally, the image displays vibrant colors on the record, an effect known as thin-film interference, which happens when light waves reflect of thin pieces of metal, giving off colorful displays. 
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