Kilogramme-metre

At 50 % cold work, the Shock Resistance reaches almost its minimum value. In the annealed state, the Shock Resistance varies between 8 and 8-5 kilogramme-metres per sq. cm., without any appreciable difference between test pieces cut longitudinally or transversely. This difference, however, becomes more marked as the cold work increases. 

In the case of Hardness and Cupping Tests, no conversion has been attempted, the metrical values being in general use in this country. As regards Shock Resistance also, no conversion has been attempted. On the Continent the term Resilience is employed to denote the energy absorbed in impact, expressed in kilogramme-metres per square centimetre of cross section of the test piece at the bottom of the notch, whilst in this country, it is employed to denote a different property. The area of cross section at the foot of the notch... 

Assuming that the conversion from kilogramme-metres per square centimetre to foot-pounds is an arithmetical possibility, the figures would still not be comparable, as the numerical value depends to a very great extent on the precise form of the test piece employed, especially on the angle and radius at the foot of the notch, which is different in British and Continental practice. 

Mass, length and time are commonly used primary units, other units being derived from them. Their dimensions are written as M, L and T respectively. Sometimes force is used as a primary unit. In the Systeme International d Unites, commonly known as the SI system of units, the primary units are the kilogramme kg, the metre m, and the second s. A number of derived units are listed in Table 1.1. 

Energy and work have units of force time distance, such as a Joule, which is a Newton metre. Energy is sometimes measured as the amount of heat that must be transferred to a specified mass of water to raise the temperature of the water at a specified temperature interval at a specified pressure (e.g. 1 kcal corresponds to raising 1 kilogramme of water from 15 to 16°C). 

Pressure Temperature in °C. Calories per kg. Weight of 1 c. metre Steam in kilogrammes. 

The commonly used basic units are the metre (length), kilogramme (mass), second (time), and kelvin (thermodynamic temperature) with the symbols m, kg, s and K. 

Nitro-glycerine 778 metre tons per kilogramme. Gun-cotton 489 " " Picrate of potash 366 " "... 

In order to compare the magnitude of quantities— whether physical, electrical, or mechanical—their basic units must be defined. They may be basic (or absolute) units, such as metres (length) or kilogrammes (mass or weight), or derived units, such as volts (voltage) or watts (power). An instrument is marked off in divisions as points on a scale. 

The adoption of the international system of units, Systeme Internationale d Unites, or S.I. units for short, as the legal system in Great Britain and other countries is now complete, the system receiving official recognition at the Conference Generale des Poids et Mesures (C.G.P.M.) held in Paris attended by representatives from the National Physical Laboratory(N.P.L.) and the Bureau of Standards (U.SA.). Six basic units are involved metre (length), kilogramme (mass), second (time), ampere (electric current), kelvin (thermodynamic temperature) and candela (luminous intensity) from which other units are derived. 

The common units of density are kilogrammes per cubic metre. The density of pure water is 1, thus 1 cubic metre weighs 1 kilogramme. 

The basic SI units are the metre (m), kilogramme (kg), second (s), kelvin (K not K), mole (mol), ampere (A) and candela (cd). The mole is the unit of amount of substance and is defined as that amount of substance which contains as many elementary entities as there are atoms in 0.012 kg of carbon-12. It is thus precisely the same amount of substance as, in the c.g.s. system, had been called the gramme-molecule. Some of the SI derived units which are important in the present volume, together with their symbols, are as follows ... 

The SI base units are the kilogramme (kg), metre (m), second (s) and ampere (A). Some commonly occurring derived units are given below. 

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