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Which of the following is the correct unit for volume?
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1) meters, 2) kilograms times meters, 3) kilograms per meter cubed, 4) meters squared, and 5) meters cubed.
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To answer this, first let’s have a look at what volume actually is.
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Volume is the amount of three-dimensional or 3D space occupied by an object.
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So let’s take any three-dimensional object, preferably a simple one to make life easier for ourselves, and see what the units of measurement are for its volume.
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Let’s go with a cube.
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That’s quite easy to work with.
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So a cube has three dimensions as we know.
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The first one being its width.
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The second one being its length.
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And the third one being its height.
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Now because this is a cube and not a cuboid or any other 3D shape, the width, the length, and the height in this case are exactly the same as each other.
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However, that’s not the point.
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What we’re trying to do here is to work out how the volume of this cube is calculated.
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Well, we know that we need to multiply the width by the length by the height to get the volume of the cube.
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And since each one of these is a length, the standard unit of measurement is meters, in all three cases.
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Therefore, in order to find the volume when multiplying meters by meters by meters, or in other words, this is meters cubed.
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And so, our final answer is meters cubed.
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Let’s quickly go through the other options to make sure that we haven’t done anything wrong.
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The first one, meters, well that’s just a unit of length.
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Whereas, we want a volume.
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So that can’t be right.
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So the second one, kilograms times meters, well we’ve got meters in there which is a length.
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But we’ve also got kilograms which is a measure of mass.
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Volume has nothing to do with mass.
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Volume is simply the amount of space.
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So that can’t be right either.
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The third one, kilograms per meters cubed, now we’ve got meters cubed in there which is a volume.
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But we’ve got kilograms per that unit volume.
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That’s actually a density.
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So that’s also not right.
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The fourth one, meters squared, that’s close.
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That’s basically like multiplying the width by the length of a 2D object.
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But that’s only the area.
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That’s not the volume.
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We need to multiply that area by a third dimension in order to get a volume.
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So that’s also not right.
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Which means that we can safely say that meters cubed is the right answer.