Northeast High School - Nor Easter Yearbook (Kansas City, MO)

Page 31 text:

' 'ri-: 'Hives-921124:-l:--2-.xii-1 2-waexzwfa-:e:frm'i:-155-o.'.r,a.,,,,, .. 2 63,53 ,,. ,Im L 1165 7 . 3720 00-72 . 72- per 305f I4 14 feet Bcity v of ffer- :rent ong- :hers ona- ienv s, to Lvoid VVe open Xvill the ever e. 22 said it of 1 the fould show ap it aeast ckin- their : and I2 Pm The The en in . The it for first OID' 83.511813 27 Northeast representation in that paper. The school Science and Mathematics Monthly, as the name implies, is pub- lished every month during the school year. Several interesting topics are always printed as well as problems and their solutions in both fields of Science and Mathematics. Every issue con- tains a problem capable' of being solved by the average high school student, not only in America, but over the whole world. The last issue even con- tained a solution for the above proh- lem by Richard Cumming from Dal- keith, Scotland. . So you see that the name Northeast High School, Kansas City, Missouri, and its representatives, does travel outside of its own vicinity. ARTS AND SCIENCE EDITOR. CGNCERNING CHEMISTRY .We would not be far from wrong if we said that the study of chemistry has advanced more in the last century and a half, than it has since its begin- ning. The ancients studied chemical actions, and the art of changing some baser metal into a more precious metal. This study was called alchemy. We therefore have no old laws in chemis- try, as for instance, Archimedes Prin- ciple in Physics which has stood the test of the Twentieth Century scien- tists. ' ' ' ' The entire reason for this lies in the fact that the most important chem- ical action, namely: burning, was not understood until the middle of the Eighteenth Century, when Antoine Laurent Lavoiser discovered the chem- ical change which a metal undergoes when heated in air. He took a quan- tity of mercury, and heating it to the temperature just below the boiling point of mercury C357OCj, noticed that after a few days, a red powder was formed Qmercuric oxidej. On weigh- ing this mercuric oxide he found that it weighed more than the mercury. Then he took this mercuric oxide, an-il, heating it for several days to a tem- perature above the boiling point of mercury, found that a quantity of gas was evolved, and that small particQes of mercury were clinging to the sices of the vessel. The evolved gas he called oxygen. Un again weighing tfie mercury he found that it had the same weight as the mercury with which he had started. Then on weighing the gas he found that the loss of weigfit of the mercuric oxide was equal to the weight of the oxygen. On investigat- ing further, he found that in burning, the weight of the entire products ex- ceeds the weight of the fuel. And with these experiments, and experiments of similar nature by other great scien- tists, such as Joseph Priestly, who was a contemporary of Lavoiser, the study of chemistry was revolutionized. Lavoiser, in 1786, was the first to explain ordinary burning as the com- bining of a substance with oxygen. Such a combining is an oxidation and the compounds formed are known as oxides. There are four different kinds of oxidations, namely: ordinary burn- ing, slow oxidation, spontaneous com- bustion, and explosion. Qrdinary burn- ing is an oxidation accompanied by noticeable light and heat. Take the case of a burning candle fone of the most interesting lectures was given by Michael Faraday at the Royal Institu- tion in London on The Chemical His- tory of a Candle j, we notice the light and heat but do not realize that a chemical change is occurring. Neither would we believe that the gaseous products which are formed, will weigh more than the candle itself unless we were actually shown that such is the case, as was demonstrated in the chem- istry classes. Even then it is hard to believe. This increase in weight is due to the oxygen taken out of the air. In ordinary burning nearly all substances undergo similar changes. In slow oxidation, no noticeable light or heat are evolved.. Neverthe- less the same kind of action is taking place in slow oxidation, the only dif- ference, as the name implies, is that if goes on at a much slower rate. Let us take, for instance, the rusting of a tin can, which really should be 1 1 -. . . . . . . . . . - - - - . ' ' - ' ' :' ' ' - ' .4Z.. : , ..'f'i?1i:'S'EiEiT?ifi7'r -:f:L1?z1f1 'T L55 ' 151' ' -:V f - -- '

Page 30 text:

26 OP' QELSTC-il? VC13-d55 lil in the equation v2MVfm for V, we have Vilxlvlzg 1 1-VC19-C125 Hfm. It will be seen, however, that this for- mula is inconvenient, especially when using logarithms, as it is necessary to take the square root of a square root. By the use of 'trigonometry a much shorter formula may be obtained, which eliminates the ex- pression VC13-d95. C15 sin a2df1 Cthe sine of an angle in a right triangle equals the opposite side di- vided by the hypotenuse5, From this equation, since d and 1 are both known, we can find the sine of oi. Then, by a table of sines and cosines, we can find the cosine of CL. C25 cos cL2OBf1 Cthe cosine of an angle in a right triangle equals the adjacent side divided by the hypotenuse5. C35 OB:1 cos a Csolving C21 for OB5- C45 1-OBZ1-1 cos a Cequals subtracted from equals are equalj, C55 1-OB2l C1-cos 005 Cfactoring 1-1 cos in equation C415 C65 1-OB:S Cby figure, since OC equals 15. C75 S11 C1--cos a5 Csubstituting S for 1-OB in ' C85 v2MVfm Csee geometrical proof5. C95 V: V C2 S5 Cs ?e geometrical proof5, C105 v2MVC2 g S5!m Csubstituting C91 in f815. C115 v:11V1sVIi2 g 1 C1-cos cc5jfm Csubsti- tuting for S in C1015 Wve took the necessary measurements for finding the velocity of the bullets. In tak- ing these measurements we neglected the errors caused by the blast of air that comes out of the barrel of the gun and the weight of the bullet, which was added to the weight of the pendulum, because of their infinitesi- mal values. A piece of paper CP5 between the pendulum and the revolver will stop the blast of air from affecting the velocity of the pendulum. The measurements were taken after Mr. Pinkney said: Now open your mouths. They are: Calibre M 1 m d .22 12 lbs. 305 cm. 2.0 g. 2.375 in, .32 12 lbs. 305 cm. 5.5 g. 5.25 in. .38 12 lbs. 305 cm. 9.4 g. 10.5 in. The acceleration due to gravity at Kansas City, MO., is 32.1514 ft.fsec. 2-exponent. In calculating the velocity of these bul- lets, the measurements must be in pounds and feet to have the result in feet per sec- ond, or in grams and centimeters to have the result in centimeters per second. The vC1OCity Of the .22 is worked by trigonometry and logarithms, the .32 by 'geometry and logarithms and the .38 by geometry and the usual arithmetrical process. The computations, substituting in the for- mula, are: C.225 log sin ClilOg .l9625Cl0'.007. 21.29281-1.00030 12.29251 6. By table of the logarithnzs of sines and cosines of angles, log cos a21.9899 then cos 66209998 1-cos di -0002 , Then, VI125! C2 - 32.1514 - 10.007 ' .00025 7 .0044092 log v21.07918 -l- 1f2C0.30103 -lr 1.50720 + 1.00030 -lr 4.301035-3.64436 log v22.98960. v2976.34 feet per second. C.325 Vi12V I:2 - 32.1514 4 101007-V C10.0072. --.437525 H C.325 VZ12V C2 - 32.1514 110.007-V C100072- .4-375251 5!-012125 I9.62255f.012125: 793.62 feet per second. - C385 V':12Vli2 ' 32.151 4 305730.48-VC305f I 30.482-105971235 H ' 453.6794 212V 164.302 4 1000656167- V C100.l3127-.87535 l 17020723104 2188467447 .fQ0723104 2 909.45556 feet per second. It probably seems queer that the velocity of the .22 is greater than the velocity of the .32 or .38. But this is due to the differ- ence between the barrels of the different revolvers. The .22 that was us Ed was a long- barreled army target revolver and the others were the regular .32s and .38s. The detona- tions of these revolvers caused the mem- bers of these classes, especially the girls, to assume strange postures, so as to avoizl any unpleasant effects on the ears. We laughed and laughed at each other's open mouths and ridiculous attitudes. We will always remember this experiment as the most pleasant and interesting one we ever performed under Mr. Pinkney's guidance. MARTIN DICKINSON. 322. ' OLIN W. MUNGER '22, LE ROY SMITH, '23. Who up there inthe balcony said that the Mathematics-Department of iNtwtheastlHigh Schoolxvas notcnithe map? We wish that person would come to the front and we will show him that besides being on the map it is well represented. The names of three of our Northeast students, Fannie Roll, Martin Dickin- son and Dorsey Dsborne earned their recognition in the School Science and Mathematics Magazine by solving an algebraic quadratic equation. The problem was: X+y?23,X2+y:3. The solution by Fannie Roll was given in full in the january, 1922, number. The other two students received credit for the solution. This was not the first Ng' Ni pa M lis ye ali th an tai by nc wl 'EEL lei ke Hi 311 O11 if ha: ani nir act bas Th the try cip tes tis1 r the ica un Eig Lai icai wh titg ten poi aft- for ing it The hea per

Page 32 text:

23 or' easter called tinned can because it is nothing but an iron can covered with a very thin coat of tin. As this tin can rusts away it leaves iron oxide, or rust as it is more commonly called. This is the same product that we would derive if we burned iron in oxygen, for iron burns in oxygen. A more striking comparison can be made between two pieces of wood, one piece being burned and the other left on a wet ground to rot, or a process of slow oxidation. lf a chemical analysis were made of the products of both pieces of wood, after the chemical reaction is complete, they will be found to be composed of the same compounds and elements. Also the amount of heat liberated in both cases will be found to be the same. Another case of slow oxidation, is that which takes place in the human body. We inhale the air of which one- fifth is oxygen. Those who have studied physiology know that the blood, after having flown through the body, flows to the lungs, liberates carbon dioxide, heat, water vapor, and other impurities, and absorbs the oxygen from the air in the lungs. The blood carries this oxygen to the various tis- sues of the body. There the oxygen reacts with these tissues, forming the above named products as well as gen- erating enough heat to keep the body at a normal temperature of about nine- ty-eight degrees Fahrenheit. The same thing is true in all animal bodies. And you, who have studied physiology, have wondered why your body is al- ways compared to a steam engine. The reason for this is that the products of respiration are the same as those from any other burning. Spontaneous combustion is an oxi- dation involving both of the above mentioned oxidations. It is an actual burning started by the accumulation of heat of a slow oxidation. Oily rags. for instance, are very poor conductors of heat. A slow oxidation is taking place between the oils in the rags and the oxygen in the air. Heat is evolved, the same as in the human body, for in a case of slow oxidation, as well as in the other oxidations, there is alwaye a certain amount of heat evolved, due to the fact that the molecules of both substance undergo a chemical change and in the friction thereof, a small amount of heat is generated. Since rags are poor conductors of heat, this heat accumulates until the kindling temperature of the rags fthe lowest temperature at which a substance will take fire in air and continue to burnj has been reached. Then, if such a pile of rags should happen to be left lying in the corner of a factory, which has no automatic sprinkler system, and the watchman is down in the engine room exchanging yarns with the en- gineer, we would see in the morning papers with great headlines, Another factory destroyed by fire due to spon- taneous combustionf' A great many grain elevators, hay stacks, hay barns, and paint factories are destroyed by spontaneous combustion. Now we come to the last but not the least of the four types of oxidations namely: explosion. Specifically de- fined, explosion is a very rapid com- bustion, accompanied by a sudden in- crease in pressure due to the increase of the volume of the gas. Let us take the case of a' cartridge about to be fired from a gun. At the head ofthe cartridge there is a primer composed of fulminate of mercury, definitely formed and shaped, and exactly weighed. The hammer of the gun as soon as it hits this primer, creates enough heat to cause this fulminate of mercury to ignite. The ignited fulmi- nate of mercury, having a much lower kindling temperature than the powder, in turn ignites the powder. As the powder burns, which it does very rapidly, a gas is evolved. It is this sudden increase in volume due to the gases formed which forces the bullet from the shell. A similar case of ex plosion is made use of in the gasoline engines. In this case, the mixture of gasoline vapor and air burns in the cylinder, having been ignited by the spark from the spark plug, and having, previous to this, been compressed. iCo11tinued on Page 647 C L st 1 ei tc w D oi fr te oi or a a su ge th at w: se ba a Dc Sc ga Se ga SC4 Se mz an 3 3 on on- sni of Fr