The intensity of the stream of energy passing per second through a square centimetre when a given pure tone is sounded is more definite and can be measured.
Thus a= 2.54 cros., or one inch very nearly.] Tables Of Surface-Tension In the following tables the units of length, mass and time are the centimetre, the gramme and the second, and the unit of force is that which if it acted on one gramme for one second would communicate to it a velocity of one centimetre per second: - Table of Surface-Tension at 20° C. (Quincke).
System they are the gramme, centimetre and second.
In.," or 14,000 grms. per square centimetre, and a similar view prevailed among high authorities more than twenty years later.
System a subdivision of the latter, viz, the gramme, is adopted, and is associated with the centimetre as the unit of length, and the mean solar second as the unit of time.
Heavier howitzers had been sent for from Japan, and on the 1st of October the first batteries of 28 centimetre (11 in.) howitzers came into action.
The kinetic energy per cubic centimetre is 2 pu t, where is the density and u is the velocity of disturbance due to the passage of the wave.
Working with two different specimens, he found that the hysteresis loss in ergs per cubic centimetre (W) was fairly represented by o 00125B 1 6 and o o0101B 1 ' 6 respectively, the maximum induction ranging from about 300 to 3000.
In many experiments, however, different inductions and frequencies are employed, and the hysteresis-loss is often expressed as ergs per cubic centimetre per cycle and sometimes as horse-power per ton.
The number of oxygen molecules per cubic centimetre determines the width of the oxygen lines, though nitrogen molecules may be mixed with them without materially affecting the appearance.
System it is that force which acting on one gramme for one second produces a velocity of one centimetre per second; this unit is known as the dyne.
The closed figure a c d e a is variously called a hysteresis curve or diagram or loop. The area f HdB enclosed by it represents the work done in carrying a cubic centimetre of the iron through the corresponding magnetic cycle; expressed in ergs this work is I HdB.
We shall regard the external force as applied in the form of a pressure X per square centimetre parallel to the line of propagation and varied from point to point as required in order to make the disturbance travel on unchanged in form with the specified velocity U.
Therefore the momentum entering through a square centimetre at B per second is equal to the momentum leaving through a square centimetre at A.
According to modern measurements the solar radiation imparts almost 3 grammecalories of energy per minute per square centimetre at the distance of the earth, which is about Iï¿½3 X io s ergs per sec. per cm.
Hence the force required to drive one gramme-molecule of sugar through water with a velocity of one centimetre per second may be calculated as some thousands of millions of kilogrammes weight.
In one experiment the jet issued horizontally from an orifice of about half a centimetre in diameter, and almost immediately assumed a rippled outline.
Centimetre, exposed perpendicularly to the sun's rays, would receive sufficient energy per minute to raise 2.54 grams of water I ° C. Langley's general determination of the constant was greater than this-3 o to 3.5 calories; more recently C. G.
A standard sodium hydrate solution can be prepared by dissolving 42 grammes of sodium hydrate, making up to a litre, and diluting until one cubic centimetre is exactly equivalent to one cubic centimetre of the sulphuric acid.
Hence his measurements are all directly comparable with modern electrostatic measurements in which the unit of capacity is that of a sphere r centimetre in radius.
Thus, if d= 1, q -1 -= -115; or for a diameter of one centimetre the disturbance is multiplied 2.7 times in about one-ninth of a second.
That is, if an amount jIo is absorbed in the first centimetre, jI 1 is absorbed in the second, and so on.
The gramme was intended to be equal to the weight of a cubic centimetre of pure water at a certain temperature, but the equality is only approximate.
Taking the centimetre, gramme and second as our fundamental units, the most convenient unit of force is that which, acting on a gramme for a second, produces in it a velocity of a centimetre per second; this is called a Dyne.
The unit of work is that which is required to overcome a resistance of a dyne over a centimetre, and is called an Erg.
The magnetic flux per square centimetre at any point (B, B, or 0) is briefly called the induction, or, especially by electrical engineers, the flux-density.
In the case supposed therefore the total force per square centimetre is H2 F =2712-f-HI+B ?r (4 7r I +H)2 8?r B2 =87r.
He made use of the expression F =Wg=27r12+HI, where W is the weight in grammes per square centimetre of sectional area, and g is the intensity of gravity which was taken as.
System is the weight of a cubic centimetre of water at this temperature.
Hence the work done on the air is (P-+zw)v, and the work done per cubic centimetre is (P+Zw)v/V.
This acceleration is denoted by g; its value at Greenwich is about 981 centimetre-second units, or 322 feet per second.
In the case of diphtheria the antitoxic power of the serum may reach Boo units per cubic centimetre, or even more.
If lo represents the intensity of the light which enters the surface, I l the intensity after passing through i centimetre, I 2 the intensity after passing through 2 centimetres, and so on; then we should expect that whatever fraction of Io is absorbed in the first centimetre, the same fraction of I, will be absorbed in the second.
We have then 11=Io(1 j) I =I 1(1j) =Io(1 j)2 1 3 =1 2 (1 - j) =Io(11)3 and so on, so that if I is the intensity after passing through a thickness t in centimetres I = Io(1 We might call j, which is the proportion absorbed in one centimetre, the "coefficient of absorption" of the medium.
The organ figured is one of the catkins (about a centimetre in length) which were borne laterally on the spike.
Where the induction is high the lines will be crowded together; where it is weak they will be widely separated, the number per square centimetre crossing a normal surface at any point being always equal to the numerical value of B.
Denoting by W the work in ergs done upon a cubic centimetre of the metal (=_fHdB or f HdI), he finds W =nips approximately, where n 47r is a number, called the hysteretic constant, depending upon the metal, and B is the maximum induction.
A very small sphere is said then to possess a charge of one electrostatic unit of quantity, when it repels another similar and similarly electrified body with a force of one dyne, the centres being at a distance of one centimetre, provided that the spheres are in vacuo or immersed in some insulator, the dielectric constant of which is' taken as unity.
According to Quincke, the surface tension of pure water in contact with air at 20° C. is 81 dynes per linear centimetre, while that of alcohol is only 25.5 dynes; and a small percentage of alcohol produces much more than a proportional decrease in the surface tension when added to pure water.
The total magnetic induction or flux corresponds to the current of electricity (practically measured in amperes); the induction or flux density B to the density of the current (number of amperes to the square centimetre of section); the magnetic permeability to the specific electric conductivity; and the line integral of the magnetic force, sometimes called the magnetomotive force, to the electro-motive force in the circuit.
The unit of mechanical force in the " centimetre, gramme, second " (C.G.S.) system of units is the dyne, which is approximately equal to 1/981 part of the weight of one gramme.
(76 millimetres), which denotes a variation of 103 grammes per square centimetre in the pressure of the atmosphere, the change caused thereby in the length of a standard of linear measurement would appear to be as follows: --
In diameter, found that the current given by it could only electrolyse acidulated water in 40 hours sufficient to liberate one cubic centimetre of mixed gases.
-- Decametre or 10 metres; double metre; metre or 1000 millimetres; decimetre or 0.1 metre; centimetre or 0.001 metre; millimetre.
This, at first sight, paradoxical result is explained by the fact that the mean free path of each molecule increases in the same proportion as the density is diminished, so that as the number of molecules crossing each square centimetre decreases, the distance to which each carries its momentum increases, and the total transfer of momentum is unaffected by variation of density.
He has also found that this action is reversible, for when the area of the surface of contact of the acid and mercury is made to increase, an electric current passes from the mercury to the acid, the amount of electricity which passes while the surface increases by one square centimetre being sufficient to decompose.
The Ferns exhibit a wide range in size from the minute epiphytic Hymenophyllaceae, with leaves barely a centimetre in length, to gigantic tree-ferns 80 ft.
A unit magnetic pole is that which acts on an equal pole at a distance of one centimetre with a force of one dyne.
In a uniform magnetic field of unit intensity formed in empty space the induction or magnetic flux across an area of I square centimetre normal to the direction of the field is arbitrarily taken as the unit of induction.
In one case the hysteresis loss per cubic centimetre per cycle was 16,100 ergs for B =1 5,900, and only 1200 ergs for B = 20,200, the highest induction obtained in the experiment; possibly it would have vanished before B had reached 21,000.2 These experiments prove that actual friction must be almost entirely absent, and, as Baily remarks, the agreement of the results with the previously suggested deduction affords a strong verification of Ewing's form of the molecular theory.
It is better then to define the coefficient of absorption as a quantity k such that kln of the light is absorbed in i/nth part of a centimetre, where n may be taken to be a very large number.
Hence if the induction per square centimetre at any point is denoted by B, then in empty space B is numerically equal to H; moreover in isotropic media both have the same direction, and for these reasons it is often said that in empty space (and practically in air and other nonmagnetic substances) B and H are identical.
Rotation period; latitude o° :24.46d 300:26.43d 60°:29.634 80°:30.56d Solar constant, or units of energy received per minute per square centimetre at earth's mean distance: 2 I calories.