Wednesday, July 27, 2016

Daily Regents: Volume and Density (August 2015)

Even though the title says "Daily", I won't be doing them daily any more, until the exams get closer. But they will be frequent.

Geometry, August 2015, Question 25

25. A wooden cube has an edge length of 6 centimeters and a mass of 137.8 grams. Determine the density of the cube, to the nearest thousandth.
State which type of wood the cube is made of, using the density table below.

Density is defined as Mass divided by Volume. (d = m/V). You are given the length of one edge of a cube. The volume of the rectangular prism = length times width times height (V = L * W * H). However, with a cube, all three values are the same, so V = s3.

Density = mass / Volume. Volume of a cube = (edge length)3.
If you substitute the values that we know, we find that Density = mass / (edge)3 = 137.8 / (6)3 = 0.63796..., which rounds to 0.638.

According to the table, the approximate value of Ash wood is 0.638.
The wood is Ash.

Note: Don't forget to identify the wood after finding the density, even if you just circle the correct answer.

Also: If you get "Ash" without showing any work, you will NOT score a point.

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