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Guide
1
To find body weight, you need to multiply its volume by the density of which can be found in reference books.Figure 1 shows the density of common substances.Note that the values ​​specified at a certain temperature, i.e.If you want to find a lot cooled or heated matter, you have to take it into account in the calculations.
2
remains to find the volume.Based on the fact that the area known, you can find the volume of the standard formulas for a variety of geometric shapes.Thus, the volume of the box is a direct product of the area of ​​its base and the height.The volume of a sphere can be found by dividing the area sphere, raised to a power of 3/2, in a work of six and the square root of π.The volume of a cone - dividing the product of t
he square base of the cone and its height three.Cylinder capacity - by multiplying the area cylinder base to its height.
3
As can be seen, only in the case of a ball can derive the formula, which is used exclusively area of ​​its surface, in other cases, additional parameters.
To overcome this difficulty you will have the support of the cube.His ribs are of equal length, so the total area surface is equal to 6 * a ^ 2.Hence, the well-known square, you can find the length of the edge, it will be equal to the square root of S / 6, where S - the total area surface of the cube.Now you can find the volume of a cube, erecting the resulting length of the edge in the third degree.
4
Knowing surface area of ​​some figures, you can imagine a cube with exactly the same area th surface and find its volume as shown above.It will be equivalent to the volume of the body area th surface.
5
Thus, knowing surface area of ​​even very complex shapes, you can always reduce its volume finding to finding the volume of a cube of equal area.Then you can find a lot of , multiplying this value by the density of matter.Of course, this method will have a significant error, but the approximate weight object you can find.