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The Big Race



Just yesterday in class it seemed everyone had a good time racing some cans that they though would go the fastest. However, there were a few unexpected victors in the bracket as we saw the two walk-ons: Orange Gatorade and Mr. Temple's water bottle reach the finals, with the Orange Gatorade getting the dub in 3 matches. Why was this?

In general, we know that the higher the mass and radius of the can, the faster it will go (i.e. its Moment of Inertia). We know the moment of inertia of a cylinder is MR^2, thus the radius having a much larger impact on the can's inertia that its mass ultimately. If we judged the races by each can's moment of inertia see who would in, chances are that Miss Huppe's German Potato Salad (GPS) would've brought home the gold. However, the Orange Gatorade knocked out the GPS for some reason or another, even though the GPS has a higher moment of inertia as well as an initial potential energy. After some class discussion we realized that there was a direct correlation between the density, or state of matter inside, and the success of the can/cylinder. The proper term for this difference in thickness would be the substance's viscosity. A substance's viscosity is determined by its resistance to flow. For example, maple syrup would have a much larger viscosity than water would. Therefore, if you had two equally filled identical cans - one with maple syrup and one with water - the one with water would go the fastest each time. This is because when a substance is more viscous than another, there will be more residue on the top of the inside of the can than the other. If you were to fill a clear water bottle partially and watch it roll down a ramp, you would see that the water would settle to the lowest point of the water bottle. The Orange Gatorade's traveled faster than the GPS and all its other opponents because of its state of matter inside which allowed it the least resistance and loss in energy during its motion.

Even when we thought we knew which was going to win, the underdog claimed the victory!


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Might want to go revisit what "Moment of Inertia" is again and what it means qualitatively.  Good start, but a couple of conceptual inconsistencies here that would be good to iron out.  :-)


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