As the main method of determination of body weight – weighing, in life of a concept of body weight and body weight became synonyms for a long time. As a rule, when body weight is mentioned, its weight is meant. In physics it is powerful force of impact of a body on a suspension or a support which arises because of a gravitational attraction of Earth is called. Body weight can will change in pretty wide limits – beginning from zero gravity and finishing with huge overloads. The mass of a body – almost constant characteristic of a physical body.
It is required to you
- calculator or computer
Instruction
1. To translate the mass of a physical body set in tons in its weight (in kilonewtons), increase the number of tons by number 9.8 (acceleration of gravity). That is use the following formula: KN = Kt * g, where: Kt – the number of tons, Kkn – quantity a kilonewton, g – acceleration of gravity (≈9.8m/with²) (the m/s²) cannot pay attention To dimension of size g. For obtaining more exact result use "exact value g: 9.806652.
2. Example. In a tank there are 60 tons of water. The mass of an empty tank – 1 ton. Question: What weight of the filled tank? Decision: (60+1) *9.8 = 59.78 (kilonewton). The calculations made on the above-stated formula are fair only for "normal conditions, i.e. near the earth's surface, far from geomagnetic anomalies and provided that can be neglected the pushing-out gas force (or liquids).
3. If the body is in liquid, then it is affected by the pushing-out force equal to weight of the liquid which is forced out by a body. Therefore, for transfer of tons to kilonewtons for the body shipped in liquid use the following formula: KN = Kt * g – Vzh, where: Vzh – the weight of the liquid which is forced out by a body. Example. Metal preparation weighing 2 tons is placed in a tank with water. The weight of the liquid which is forced out by preparation was the 5th kilonewton. Question: What will be preparation weight in water? Decision: 2*9.8 - 5 = 14.6 (kilonewton).
4. As the weight of the forced-out liquid depends on its density and volume of a body, it is possible to use the following formula: KN = Kt*g – Ob*Pl*g * = g * (Kt – Ob*Pzh), where: About – the body volume, and Pzh – liquid density, at the same time, the volume of a body has to be presented in cubic meters, and liquid density - in tons on cubic meter.
5. If instead of volume body density is known, then use the following formula: KN = Kt*g – Kt/Pt*Pzh*g * = Kt*g * (1 – Pzh/Pt), where: Pt – body density (in tons on cubic meter).