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course Mth 271
Solve using proportionalities by stating the appropriate proportionality law and finding the proportionality constant: * If a sand pile 2.1 meters high has a mass of 5000.939 kg, then what would we expect to be the mass of a geometrically similar sand pile 6.1 meters high?
* If there are 1.323 billion grains of sand exposed on the surface of the first sand pile, how many grains of sand we expect to be exposed on the surface of the second?
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5000.939 = a * 2.1^3
5000.939 = a * 9.261
a = 539.999
y = 539.999 x^3
y = 539.999 * 6.1^3
y = 122569.7155
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y = a x^3
1.323^3 = 2.316
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@& The mass of the sand occupies its volume, and you got that part right.
Grains are exposed only if they are on the surface. Your answer to that question treats them as if grains inside the pile are exposed on the surface, which is not the case.
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