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its density. 15. A wooden raft 5 ft. long and 4 ft. wide floats in water. When a person steps on the raft it sinks 1.5 inches deeper into the water. Calculate the person’s weight. 16. A cork of volume 60 c.c. and density 0.24 gm. per c.c. floats in a liquid of density 0.85 gm. per c.c. Find the least weight required t... |
techniques used in measurement. A. — Use of the ruler 1. Avoid using the ends of the ruler. 2. Place your eye directly above the point where the reading is to be taken to avoid the error due to parallax. B / Measuring Length with a Fig. 5:1 Ruler—How to Avoid the Error Due to Parallax. Fig. 5:2 Measuring Volume with a... |
Questions 1. What is the correct value for the density of this material? (Table P-21). 2. Express the difference between the class average and the true value as a percentage of the true value. This is a measure of the experimental error. 3. Suggest sources of experimental error. * Note The density of other regular sol... |
3. Suggest sources of experimental error. 4. If the balance at your disposal is suitable, a graduated cylinder, instead of a beaker, could be used in steps 1 and 2 in the above experiment. Why should this tend to reduce the experimental error? EXPERIMENT 4 To determine the specific gravity of a liquid by means of the ... |
in step 2? 2. Why was the equilibrium restored in step 3? 3. State Archimedes’ Principle. Questions 1. Why do objects apparently weigh less when immersed in a liquid? 2. What would be the effect of immersing the object in a denser liquid? EXPERIMENT 6 Alternative method to demonstrate Archimedes' Principle. (Ref. Sec.... |
of the object does not touch the beaker. when immersed in water. 3. Repeat the above weighings for other objects supplied and fill in the table below. Observations Object Weight in Air Weight in Water Apparent Loss IN Weight 1. 2. 3. Calculations Weight of object in air = Apparent loss in weight = Weight of water disp... |
) Apparatus Balance, paraffined wooden block, overflow can and catch bucket, water, other liquids. 43 Chap. 5 MECHANICS Method 1. Place the overflow can on the pan of the balance. Fill the overflow can to the spout with water (Exp. 6). Balance it. 2. Without adjusting the weights, and after placing the catch bucket und... |
To determine the specific gravity of a liquid using a hydrometer, (Ref. Sec. 1:13) Apparatus Several tall cylindrical vessels, several liquids (brine, alcohol, etc.), three hydrometers (one for heavy liquids, one for light liquids, one universal) Method 1. Float an appropriate hydrometer in a cylinder containing the l... |
. Yet, although Aristotle and the early philosophers knew something of the physical nature of sound, it is only in the last four or five hundred years that a fuller understanding of it has been gained. [ j i The word sound has been used frequently already, but no effort has so far been made to define it. One definiit t... |
e the same period. It is for this reason that the pendulum is used in For that physics as a timing device. reason also, it is the primary component of large clocks. Were you to experiment with pendulums of different lengths, the period of a short one would be less than It is for this reason that of a long one. that you... |
. (Sec. IV : 38), which include light waves, are also transverse in character. Fig. 6:6 shows the displacements of the particles of a medium transmitting a transverse wave. Particles at the crests (B, F, etc.) of the wave are undergoing a maximum displacement upwards, those at the bottom of the troughs (D, H, etc.) a m... |
: 5 represents the distance that the motion has travelled during the execution of one com]3lete vibration. Period of a \ ibratioii is the time of one complete vibration, or is the time taken by a particle in travelling from its mean position through the maximum displacement first in one direction and then in the other,... |
stretched between two supports (S, Si). A piece of cloth is tied near its centre. When several coils of the spring are squeezed together a compression, formed. When the coils are released, their elasticity causes them to return to their normal position. The momentum so produced causes them to move past this position, ... |
Waves A very important case of interference is seen when two trains of waves of the same frequency and amplitude travel in opposite directions through a medium, for example, original and reflected waves (Chap. 10, Exp. 5). To demonstrate this, attach a light flexible silk cord to one prong of a large tuning-fork. Pass... |
of phase as in (a). We know that the result will be Onea line of undisturbed particles. quarter of a period later (b), each will have shifted one-quarter wave-length but in opposite directions. -The waves will be in phase now and will reinforce each the resultant other. has wider amplitude than either of the original ... |
person standing at the focus of the other. Echoes are due to reflection. They are produced as the result of a sound 58 PRODUCTION AND TRANSMISSION OF SOUND Sec. II: 8 all etc. will sides, signal directed towards a distant ob(e.g., a wall) being returned to stacle the listener, who thus hears a repetition of the sound ... |
same individual from time to time, and also even with the loudness of the sound. If the cannon is one mile from the obtake about 5 server seconds to travel the distance, and hence a personal error of 1/5 second will introduce an error of four per cent in the the watch, and hearing the sound will final result. 59 Chap.... |
so the velocity of sound can be It should be noted that since found. the sound signal has to travel back along its track this method automatically eliminates the effect of the wind. Example A metronome was 280 feet from the interval between wall and the time clicks was 1/2 second. Distance covered in 1 /2 sec. was 560... |
states of matter and suggest a theoretical explanation for any differences. 4. (a) Distinguish between transverse and longitudinal waves. (b) Define: amplitude, wave-length, period, frequency. (c) By what fype of wave-motion is sound transmitted? What are the components of each complete sound wave? 5. 6. (d) What is t... |
give a distinct echo, (b) What would be the effect if the auditorium were shorter? (Assume that the temperature of the air is 20°C.] T3. A 220 yd. dash over a straight course was timed at 23.2 sec. What would the time have been had the timer started the watch on hearing the sound instead of seeing the flash? (Temperat... |
C., 23°C. 62 CHAPTER 7 CHARACTERISTICS OF MUSICAL SOUNDS 11:10 INTRODUCTION (a) How a Musical Sound Differs from a Noise As we have seen, people are quick to classify the sounds they hear, as either musical sounds or noises. Almost everyone finds noises, like the slamming of a door or the rumble of machinery unpleasant... |
caissons and diving-bells where the air is under great pressure, is that quite ordinary sounds are unexpectedly loud there. This greater intensity of the sound transmitted results from the fact that increased pressure on a gas crowds the molecules closer and increases the density of the medium. For the same reason, as... |
:3 Savart's Toothed Wheel. wheel ( Fig. 7:3) was used to show what determines pitch. The card held against the teeth of the rapidly rotating wheel received a sequence of taps, and a note, whose pitch increased with the speed of 64 CHARACTERISTICS OF MUSICAL SOUNDS Sec. 11:12 rotation, was heard. If the rate of rotation... |
occur when the origin is stationary and the observer moves past it. To determine the cause, let us take the case of the origin approaching the In any second, a uniform observer. number of wave-fronts are sent out and they will be a uniform distance apart. However, because the origin is approaching the observer, there ... |
fifth, and so on. Thus we see, as in column 3 below, that the product of frequency times the length of vibrating string is constant within the limits of experimental error. Therefore, the frequency of the note produced by a vibrating string varies inversely as its length. This is the law of lengths. Results for Law of ... |
p.s. 3. 512 v.p.s. Tension 385 gm. 1540 gm. 6160 gm. Example A string with tension of 2000 gm. produces a note with a frequency of 300 v.p.s. What would be the frequency of the note if the tension were 4500 gm.? Ratio of the new tension to the old = 4500 9, = 4 2000 ’. the frequency varies directly as the square root o... |
on. Fig. 7 : 7 shows some modes of vibration of a stretched string. one-third, fundamental when that We see that a string may vibrate in parts, and as a whole as well. When it is vibrating in parts, the frequency of the note is a multiple of that of the fundamental and the notes are called the harmonics or overtones o... |
The complicated wave forms of the others indicate that: D—Violin Fig. 7:9 Oscilloscope Tracings. 70 CHARACTERISTICS OF MUSICAL SOUNDS Sec. II : 18 1. They contain tones (overtones) in addition to the fundamental. 2. That some have more of these over- tones than others. 3. That in some, the overtones are more prominent... |
, two, and four octaves above the given note. (b) Find the frequencies of notes that are one, three and five octaves below the note. 2. A toothed wheel with 40 teeth Is rotated at the rate of 360 revolutions per minute while a card is in contact with the teeth. Calculate the frequency of the note heard. 3. A toothed wh... |
with a frequency of 300 v.p.s. What would be the frequency if length became 15.0 cm., 60.0 cm., 20.0 cm.? the 7. The A string of a violin vibrates at 440 v.p.s. The string is 40.0 cm. long from If the violinist moves his bridge to nut. finger so that only 30.0 cm. of the string vibrates, what will be the frequency of ... |
is called a closed tube, while if it is open at both ends it is designated an open tube. of the same length and period of vibration will take up the vibratory motion and move with increasing amplitude. The others that have different periods (a) The Closed Tube After performing the experiment to demonstrate resonance i... |
of the tuning-fork traces one-half a vibration, diagram (a), a condensation is sent down the tube and is reflected at the closed end as a condensation. When it reaches the open end it will be reflected down the tube as a rarefaction while the air that spills out forms a condensation the condensation pro- that duced ab... |
practice, must be augmented by.3 times the diameter of the tube (see note) but for purposes we may disregard our Therefore, wave-length (/) of sound = 4 X length of closed tube (L) giving resonance. it. Example A tuning-fork whose vibration frequency is 256 v.p.s. produces resonance with a closed tube 13.0 inches long... |
column is such that its natural period of vibration is the same as that of the fork. The boxes are placed a short distance apart with their open ends facing each other. When one fork is vibrated and then silenced shortly afterwards, a sound of the same pitch is still heard (Chap. 10, Exp. 11.) It is found to originate... |
j rarefaction (Ri) at either side. These r two waves spread out in all directions and, because they are in opposite phase, interfere with each other, producing silence when they meet at the corners (S). It is often noticed that the intensity of sound varies in different parts of an auditorium without any obvious cause... |
. 8; 7(c) Flaving studied beats with reference to transverse waves, we may understand their production in sound waves more shows two sound, waves of slightly different frequencies being produced simultaneously. Assuming that they begin in phase, two condensations or rarefactions will occur together, producing a loud so... |
-length of such a note? 3. Explain and give examples of sym- pathetic vibrations. 8. Account for the rise in the pitch of sound heard as a cylinder is gradually 4. (a) What is the cause of interference in sound? (b) Explain (i) silent points around a tuning-fork, (ii) variations in the loud- ness of sound as Herschel’s... |
'\5Vi°Q. 4. Find the length of closed tube that will respond to a frequency of 288 v.p.s., the temperature of the air being 25V2°C. Express the answer in both British and metric units. 80 CHAPTER 9 APPLICATIONS OF SOUND ing between these membranes sets them in vibration in a way similar to blowing between the strands ... |
cause hair-like projections to vibrate, transmitting small nerve impulses through the auditory nerve to the brain. In addition to the cochlea, the inner ear contains another organ known as the semicircular canals, which is associated with posture and balance. 11:28 MUSICAL SCALES The story of the evolution of the exis... |
this scale and difficulties of modulation are overcome. It should be noted that a small amount of discord is inevitably present in instruments of fixed pitch, such as the piano and organ, which are tuned according to this scale. Thus reference to the tables will show that a chord of the three notes C, E, G, which is k... |
periodic variations in pressure. The length of the pipe is adjusted so that it resonates with these and gives out a musical tone, including overtones. Being a closed pipe. Cello Violin Guitar Harp Turner Musical Instruments Lyon Healy, Chicago. Fig. 9:4 Stringed Instruments. Chap. 9 SOUND Fig. 9:5 Wind Instruments. Gr... |
use ultrasonic vibrations, best i.e., having frequencies above the audible These can be beamed and on range. being detected are of such a nature as not to be confused with other vibrations in the water. 11:33 THE FUTURE OF SOUND the No one can foresee future of sound. The properties of sounds in the audible range, tha... |
voices. (a) What are the three main divisions of the ear? Name the parts and purpose of each. (b) Describe how we hear. 3. (a) Define: tonic, octave, major tone, minor tone, semitone, major triad. (b) Distinguish between diatonic scale, and scale of equal temperament or chromatic scale. orchestra under the headings: (... |
amplitude The pendulum made shorter The pendulum made longer Conclusions 1. (a) What type of vibratory motion is illustrated by the pendulum? (b) Define complete vibration. 2. Define amplitude of vibration. 3. Define (a) frequency of vibration, (b) period of vibration. 4. What efTect has changing the amplitude on the ... |
d EXPERIMENT 3 To determine whether or not sound requires a material medium for its transmission, (Ref. Sec. II: 4) Apparatus Bell-in-vacuo (Fig. 6:5), exhaust pump, wax or vaseline, electric wires, two dry cells, switch. Method 1. Seal the bell-in-vacuo onto the pump plate with the wax and connect with the exhaust pu... |
wave-motions. 2. What are the two parts of a longitudinal wave? Define and give examples of longitudinal wave-motion. 3. Define; crest, trough, condensation, rarefaction, wave-train. 4. How is the energy from the source of disturbance transmitted through a medium? 5. What is the fundamental characteristic of wave-moti... |
ated disc and a jet of compressed air. EXPERIMENT 7 To determine the law of lengths for vibrating strings. (Ref. Sec. 11:15) Apparatus Sonometer (Fig. 7:6), one steel string, movable bridge, tuning-forks with different frequencies such as 256, 320, 384, 512, 1024 v.p.s. Method 1. Using a string 100 cm. long, adjust its... |
note the effect on the riders and the pitch of the note produced. Record your results in the table. 2. Place three riders on the string as before. Touch the string lightly at its centre and bow the string in the middle of one of the halves. Make the same observ^ations as before and tabulate them. 3. Repeat part 2 usin... |
(c) Vibrate the same fork by bowing it and striking it with the hard mallet simultaneously. Note the quality of this sound. Observations What is observed in the above parts of the experiment? Conclusions 1. What determines the quality of sound? 2. Explain in terms of superposition of waves. EXPERIMENTIO To demonstrate... |
or plasticine. Method 1. Place the tuning-forks close together with the open ends of the Strike one fork and silence it after a short boxes facing each other. time. Note what happens. 2. Strike the other fork and repeat part 1. 103 Chap. 10 SOUND 3. Load the prongs of one of the forks with wax or plasticine. Sound the... |
was struck a glancing blow with a sharp piece of flint (a hard, compact mass of silica, the mineral of which sand is composed). Both of these are a far cry from the use of such modern devices igniters etc., although ihe principle of the flint gas and still employed in as matches, electrical igniter is cigarette lighte... |
coup de grace by rubbing together two pieces of ice in a vacuum at a temperature The below the melting-point of caloric theory held that as ice contained no caloric it could not melt under these conditions. But melt it did and in doing so afforded yet more proof that heat must be a product of motion. ice. (h) The Kine... |
its brakes, the disappears enei‘gy changes to heat energy in the brakes. From this and numerous other examples, it is evident that heat is produced at the expense of some other form of energy. A brief discussion of several sources of heat (Fig. 11:2) will follow. motion which of (a) Mechanical Action Ill : 3 SOURCES O... |
universe is made up from about one hundred different kinds of elements. Elements are simple substances that have not been decomposed by ordinary chemical means. They are composed of atoms which are the building-blocks for the molecules of all sub- like those Some atoms, this energy. of stances. uranium or radium, are ... |
. 113 Chap. 11 HEAT Cornell University in 1938 showed that there is a decrease in the mass during the process and that this is converted to heat. For some time man has dreaded a world scarcity of fuel, knowing that at our present rate of consumption we shall be at that critical point in two or three centuries. Accordin... |
.000019 0.000026 0.000019 0.0000009 0.000011 0.0000088 0.0000085 0.0000004 0.0000036 *Pyrex consists of 80 per cent silica and 20 per cent various oxides of metals, chiefly of boron. 111:6 APPLICATIONS OF EXPANSION OF METALS Some applications of expansion have been mentioned already and it is clear that the expansion o... |
the temperature will be constructed. The temperature of a body may be defined as that condition which determines the direction of heat flow between it and its surroundings. Thus, a body at a high temperature will give heat to cooler objects while a body at a low temperature will take in heat from warmer objects. This ... |
the stem, leaving a vacuum in the space above it. bath, To graduate the thermometer, we choose two fixed temperatures which can be easily obtained, and mark the level of the mercury on the stem when each of these temperatures has been maintained for some little time. The temperatures chosen are the freezing- and boili... |
°F. was the lowest temperature that could be reached. The centigrade scale introduced by the Swedish scientist Celsius, in 1742, had the fixed points of 100°C. and 0°C. boilingrepresenting, and freezing-points of pure water. respectively, -the The comparison of these two scales may be seen by reference to Fig. 12:10 an... |
(Fig. 12:12). In addition, you will recall that gases expand much more than liquids 122 EXPANSION CAUSED BY HEAT Sec. Ill: 9 and solids for a given change of temperature, i.e., they have a greater coIt may seem expansion. efficient of Fig. 12:12 Expansion ond Contraction of Gases. strange, but is nevertheless true, th... |
12:12, the instrument is sealed so that the gas is maintained at constant volume and a rise in temperature causes a proportionate (Fig. This pressure change is read 12:14). directly in degrees. For low temperature work hydrogen or helium is used. Above 500°C. they would diffuse through the bulb and for this reason nit... |
2. Find the readings on the centigrade Fahrenheit thermometer scale when the reads: 100°, 350°, -220°, -50°. Fahrenheit and centigrade readings the same? (b) At the Fahrenheit reading double the centigrade reading? temperature what is 4 (a) (i) Express 57°C, — 23°C as Kelvin temperatures. (ii) Convert 298°K., 237°K. t... |
the poor conductivity of liquids does not include mercury, which, being a metal, is a good conductor. (c) Gases If the hand is held close to a Bunsenburner flame, the resulting burn is not as intense as when gripping a metal bar at the same distance from the flame. This demonstrates that air (or any gas) is a poor con... |
, the land will cool faster by radiation (Sec. 111:15) and the reverse in a land- situation will results. result breeze (i.e., off-shore). Hot-air heating systems (Fig. 13:8) depend upon convection currents for However, both the transfer of heat. bution of heat on cold windy days, when it is hard to heat the windward T... |
the shorter the wave-length. The waves are believed to be of the transverse variety which, according to one theory, are set up by a minute pulse of energy, called a quantum, from the source. These waves are a part of the great electromagnetic family of waves (Fig. 19:4) that includes visible light. X-rays, ultraviolet... |
an experiment we always find that dark, dull surfaces are good emitters of radiant energy, while light, shiny ones are poor in this respect. It is admitted that other factors, such as starting temperature and area of surface also affect the rate but for the purpose of our discussion, these were kept constant. Can Prat... |
, contained in a suitable protective carrying case. The inner glass walls facing each other are silvered. Liquids, whether hot or cold, will remain at very nearly the same temperature for several hours. The reason is that the bottle is so constructed that it is very difficult for heat to be transferred by any of the th... |
elsewhere. It is to be hoped that with this introduction to the subject, the student will be able to recognize others as he encounters them. 135 Chap. 13 HEAT Installation for radia heating ant in building. Anaconda American Brass Ltd. III : 16 QUESTIONS 1. Name three methods of heat transfer and explain how they are ... |
temperature. is repeated with one mass larger than the other (Fig. 14:1), the smaller mass will show a greater rise in temperature. If two unequal masses of water are heated to the same temperature by the same source, the larger mass will require to be heated for a longer time. is evident that temperature and quantity... |
with water? us mix two equal For example, let masses, one of water and one of iron filings, at the same temperature, with two equal masses of water, also at the same temperature. The water will give rise to the higher final temperature (see example), because it contains more heat than the iron. Hence, the quantity of ... |
= 1 B.T.U. 1F.° = 100 X 1 = 100 B.T.U. I j 1 1 Quantity of heat lost = 7000 B.T.U. Note 1. The calorie used when measuring the energy content of foods and fuels (sometimes called the kilogram calorie), is equivalent to 1000 of the calories above. 2. 1 B.T.U. is equivalent to 252 calories. Ill : 21 SPECIFIC HEAT To fin... |
70°F.? Example 2 Solution 1 Change in temperature = 150 — 70 = 80F.° Quantity of heat lost by 1 lb. of iron in cooling 1F.° =.110 B.T.U. 1F.° =.110 X 10 B.T.U. 10 lb. of iron in cooling 10 lb. of iron in cooling 80F.° =.1 10 X 10 X 80 = 88 B.T.U. Quantity of heat lost = 88 B.T.U. Solution 2 Change in temperature = 150... |
gm. and a specific heat of.22. If the final temperature is 23 °C., find the mass of the water. Mercury Water Calorimeter Quantity of heat lost by the mercury =: mass X change in temperature X specific heat = 200 X 90 X.033 = 594 cal. Quantity of heat gained by the water = mass X change in temperature X specific heat =... |
of the copper shot 100 gm. = 200 gm. = 95 °G. Initial temperature of the copper Initial temperature of the water and vessel = 15°C. Specific heat of the water Specific heat of the calorimeter Final temperature of the mixture Let the specific heat of the copper = 1 =.22 = 25.5°C. = x 144 MEASUREMENT OF HEAT Sec. 111:25... |
than inland. For example the Niagara region has a more moderate climate because of the water round it. The Prairie Provinces, on the other hand, will experience extremes of temperature since there are no moderating influences. The daily differences in temperature referred to above are also responsible for land- and se... |
quantity of water from 0°G. to 100°C., stirring constantly with a thermometer. It is found that the temperature does not rise above 100°C., although heat is being absorbed continually. The heat is being used to overcome the force of cohesion rather than the but, since until all the ice has melted. Heat is being temper... |
0°C. To determine it, the method of mixtures is employed again. A brief summary of the method, a set of typical results and a sample calculation are presented below but the method in detail will be found in experiment 8, chapter 15. Small pieces of ice that have been dried with a cloth are allowed to melt with continu... |
and to heat released by the thermometer and other parts of the equipment. With care a fairly accurate result may be obtained. The accepted value for the heat of fusion of ice is 80 calories per gram. In the British system, the heat of fusion of ice is 144 B.T.U. per pound. It is the quantity of heat required to change... |
mass of water at its boiling-point to steam without a change in temperature is heat of vaporization of water. In the metric system, the heat of vaporization is the quantity of heat required to change one gram of water at 100°C. to steam at 100°G. (atmospheric pressure being 760 mm. of mercury). Experiment 9, chapter 1... |
heat lost by the resulting water cool- ing = 21.7 X 64 X 1 = 1389 cal. 100°C. 36°G. 5'^C. M = 400 gm. S = 1 M = 100 gm. S =.22 Change in temperature = 36 — 5 = 31C.° Quantity of heat gained by the cool water = 400 X 31 X 1 = 12400 cal. Quantity of heat gained by the calorimeter = 100 X 31 X.22 = 682 cal. 151 Chap. 14 ... |
vel (Canada) Ltd. Fig. 14:9 The Operation of a Gas Refrigerator. quick-freeze units etc., all work on the same principle. (c) The Liquefaction of Gases learn more later Michael Faraday, about whom we (Sec. V:57), shall devised an ingenious method of liquefying gases. He filled a thick-walled glass tube of the type show... |
14:13 The Steam Turbine. (a) Principle of the Steam Turbine. This type of steam-engine is widely used in power-plants and large ships. 14:13). The force of the vapour rotates the paddle-wheel. are These engines 157 @ CONT«Ot «O0M (?) STATION SERVICE TRANSfORMER © ELECTRIC' GENERATOR © CONDENSER ©TURBINE ©BOOSTER PUMP ... |
Diesel Engine This engine operates like a four-stroke gasoline engine but is without carburetor or electrical ignition system. Air is 159 Chap. 14 HEAT to about one-sixteenth of forced into the cylinder and is compressed its volume and for that reason becomes hot. When oil is forced into this hot gas, it burns, withou... |
experiment to find the specific heat of a metal. (b) When a 200 gm. mass of metal at a temperature of 85°C. is immersed in 300 gm. of water at 30°C., the final temperature is 33°C. Calculate the specific heat of the metal. 5. (a) Distinguish between boiling and evaporation. (b) Define melting-point and boiling- point.... |
1 3°C. are contained in an aluminum calorimeter weighing 50 gm. If 35 gm. of glass at 87°C. are dropped Into the calorimeter the temperature becomes 21°C. Find the specific heat (a) Explain the principle of operation of the glass. of the electric refrigerator. (b) How is air liquefied? B 1. How much heat is required t... |
100°C. are added to 400 gm. of water at 10°C. in a copper calorimeter having a mass of 80 gm. 16. A copper calorimeter weighing 65 gm. contains 30 gm. of turpentine at 15°C. When 45 gm. of Iron at 98°C. are placed temperature becomes 32°C. Calculate the specific heat of the turpentine. 17. How much ice af 0°C. can be ... |
. of water at 6.0°C. contained calorimeter weighing 45 gm., the resulting tempera- aluminum an in 27. If 15 gm. of steam at 100°C. are added to 150 gm. of water at 20°C. in a calorimeter (S.H. = 0.10) weighing 75 gm. the final temperature is 74°C. Calculate the heat of vaporization of water. 28. When 160 gm. of water a... |
. Gradually open the air inlet until you have the desired flame. If the flame “strikes back”, i.e., burns at the bottom of the (b) mixing tube, turn off the gas and repeat (a) above. 163 Chap. 15 HEAT 3. Regulating the Size and Temperature (Colour) of the Flame (a) The size of the flame may be changed by increasing or ... |
metals when heated. (Ref. Sec. Ill: 5) Apparatus Bunsen burner, compound bar consisting of strips of copper and iron fastened together, cold water. Method 1. Heat the long straight compound bar in the Bunsen-burner flame and note any change. 2. Cool the bar in cold water and again note the change. Observations 1. Desc... |
, cold water, potassium permanganate. Method Fill the beaker with water and place it on the ring attached to the stand. Make sure that the water is at rest. Drop a crystal of potassium 166 EXPERIMENTS IN HEAT permanganate into the water near the edge. Using the tip of the low Bunsen flame, heat the liquid beneath the c... |
EXPERIMENTS IN HEAT Conclusion What effect has the nature of the surface on its ability to absorb radiant energy? Questions 1. In experiment 5, why were the bulbs of the differential thermometer darkened? 2. In experiment 6, why is a dull, dark vessel used? 3. Why do people wear dark clothing in winter and light-colou... |
observations recorded above. Conclusions 1. What is your experimental value? 2. What is the class average? Questions 1. What is the percentage error? 2. What are the sources of error in this experiment? 3. Why is it desirable to have the initial temperature a few degrees lower than room temperature? EXPERIMENT 8 To de... |
, Bunsen burner, retort stand, ring, gauze, steamboiler, steam-trap, rubber connectors (Fig. 14:6). Method Place the boiler containing water on the ring of the retort stand and heat it. 1. Find the mass of the inner vessel and stirrer. 2. Put about 100 ml. of the cold water into the inner vessel and find the combined m... |
to whether these particles originated in the eye or Plato (428-348 in the object viewed. B.G.) and Euclid (about 300 b.c.) held to the idea that invisible feelers were emitted from the eye, and that the eye sees a body somewhat as the hand may feel it with a rod. The Pythagoreans, Aristotle (284-322 b.c.) in particula... |
or scatters the light so that we cannot see clearly objects on the other side. Opaque substances, like wood, do not transmit light at all and hence we cannot see through them. is common knowledge that light travels in straight lines. Our inability to see around corners, the formation of shadows, and other examples poi... |
seen on the translucent screen. \ / / \ (a) Fig. 16:2 Rectilinear Propagation of Light (a) Ray (b) Beam (c) Converging Pencil. (d) Diverging Pencil. 177. Chap. 16 LIGHT however, because of the small amount of light admitted through the pin-hole. IV : 5 SHADOWS AND ECLIPSES A shadow is the dark space behind an opaque o... |
as shown in 16:3 Fig. establish these relationships fairly readily. If we replace the translucent screen with a light-sensitive paper, or photographic plate, quite acceptable photographs of distant objects can be obtained. A very long exposure is necessary, 178 Fig. 16:4 Shadows (a) Using Point Source. (b) Using Large... |
Ei to E 2 ) and shorter when Earth was approaching (going from Eg to E^, Fig. 16:6). Romer ascribed the discrepancy to the time required for the to diameter of the earth’s orbit. The timelag was found to be about 16.5 minutes or approximately 1000 seconds. Since the diameter of the earth’s orbit is about 186,000,000 m... |
energy travel through space. It is interesting to note that the vast distances of space are measured in terms of the light-year. This is the distance travelled 180 NATURE AND PROPAGATION OF LIGHT Sec. IV: 7 by light in one year. Some of the more distant stars and nebulae are so remote from the earth that the light by ... |
the wave theory was to show that the velocity of light is smaller in the denser of two media. The corpuscular theory had predicted the exact reverse of this. Recent work seems to favour a combination of the corpuscular and wave theories in the explanation of many of the observed effects. This theory called the Quantum... |
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