Density call the mass of substance falling on unit of its volume. Any physical body can be presented as the substance which is in strong aggregate state. It is accepted to designate density by the Greek letter ρ.
It is required to you
- - a subject which density needs to be calculated;
- - scales;
- - measured ware;
- - measuring tools.
1. Determine body weight. Use for this purpose scales which class of accuracy corresponds to the necessary accuracy of measurements. For weighing of very small objects it is possible to use pharmaceutical scales. If a subject large, usual store scales approach.
2. Measure body volume. Remember mathematical formulas which are applied to calculation of volumes of different solids. For calculation of volume of a cube it is enough to you to measure one side also build the received size in the third degree. To find parallelepiped volume, measure length, width and height and multiply them. Prism (straight line and inclined plane) and parallelepiped: At a prism the volume of V is equal to the work of the area of the basis on height, that is V=S*h. At a regular pyramid and a direct cone the work of the area of the basis on height needs to be divided into 3.
3. The body can be also irregular shape. Look whether it is impossible to divide mentally it into several parts, the correct solids having the form. If this is so, take necessary measurements, calculate volumes of all parts and put the received results. It will also be the volume of an initial body.
4. On production and in life quite often it is necessary to deal with bodies which cannot be divided into separate fragments of the correct form in any way. In this case use Archimedes's law. Pour water in a measured vessel so that from above there was a space. Define how many in a water vessel, and lower in it a body. Look as far as vessel contents volume increased. Subtract the first from the second indicator. According to Archimedes's law, volumes of a body and the water which is forced out by it are equal.
5. Calculate density of substance of which the body consists. For this purpose divide the weight already known to you into volume, that is ρ=m/V. If the body consists of pure substance, you can define from what. For this purpose it is necessary to find the received result in the table of density.