真四第張五第日二初月二年卯乙层
育教僑華
物理科(十八)
Solution
PHYSICS (18)
WAH KIU YAT PO
graph, Midway between 1 and N iam where the layera on either side are both displaced by the same, amount. Pressure at is normal.
Tonclusion: As sound wave passes.
the compression and aLong
er at places where
refactions appear the air # the displacement, S.,
layer de zero. The pressure is nomal at places where § is maximum
(c)
1.(a) The glass tube is
placed well down in
water and gradually maleed. As this is done a vibrating fork
held over the mouth
Whab
of the tube.
resonance occurs (a Toud volume heard The length. 11 日 menaurad.
The tube ie
now further raised up
and a second position of resonance
recorded"
With and correction as
o and wavelength of
the note as λ;
4=24+0
301210
(2)-(1)
λ = 2(12-14)
(1)
since velocity of sound; freq. x. wavelength
Therefore ▼ 21 (12-14).
(b)
ance
MAA
Since layers of air are moving when a waye passes. There must be avariation of pressure of air Diagram: (1) arid" (2) relate the dieplacement of air
air layers and the
direction of displacement. Plebiscemant
ment of Layer L is 2820, since it is compressed equally on both side. The Layer here is denoted by C, compression.
pressure here is
greatest,
co rmesponding peak-ot..
The
The
oh (3)
indicates it Displacement o
.of.
layer: A la again zero. The layer ito the left of u la-displaced to... the left while the layer to the right of N is equally displaced the lother way.
: Consequently, the ads
here is rarefied, and is denoted by R in (2).- Barefaction forUE
valley in the pressure-
A
distance
frue lines: fhet harmonie Dotted line: second harmonic
10.85m.
for at harmonic
ar fundamentals x = 2 ×0.85
= 1.7
for 2nd harmonic or 1st overtone"
B
0.85m
.340·
= 400 HK 0.85
2. (a) Progressive and stations w
In a plane progressive Wave, each layer vibrates with constant ampli- tude at the same frequency, and that cach layer is out of phase
ith athere near to it..
In a stationary wave, sona leyers (nedes) are permanently at rest;
jthers be tween the nodes are
Fibrating in phase with different amplitudes, increasing to a maxinui at the antinodas.
A stationary wave is set up when two plane-progressive waves of equar amplitude and frequency travel in Jipoaite directions in the same: nedium.
(b) Prequency of a vibrating stringali varios directly with, the square
Thus, sfite tension, Ji,
2
IX/TOT
When 256.
c (3+)
wheza w de the weight of the pane
when f512,
Therefore,.
2562 OC (3+*)
5122
2(15+1)
15+
3+w
15+7
·4(3+)
154 3w=3
The weight of the pan is 1 kgf
When unload ed, the string le stretched by the weight of the pan only. The tension is now 1 kgf. The frequency of a note, I, produced a:~
25128 Hz
It will emit a note of 128 Hz (o) Wire A sounde a fundamental note of frequency
Thus, fa
Wire B. sound :
bf. frequency
and foc
a fundamental note
報日僑
When A and B are in unison,
B
and 1T = constant
(length of wire B doesn't change. and the tension of wire A is kept ponstant.)
therefore InvTg = :constant
If In becomes
T becomes
The percentage orange: intension
of wire. B 181-
100 x
~A~ By = (1++7)(1 − +-7)*100%
2.1 x 0.1. (1.4)2.
x 100%
17.4%
To restore the unison, the tension in wire should be reduced by 17.4%
Questions for this week 1.(a) Give the outline of the
molecular theory of magnetism and use it to explain`·
(1) the saturation of magnet-
调
(ii) the demagnetization of a
magnet
aet by heating, and (iii)breaking a wagnet becomee
two magnets.
(b) Describe with the aid of diagrams how to distinguish t three identical metal roda; one
one. copper while the other
Magrietic Bubstance. Thread, compass, and iren filings are not given.se
and Y are coils of equal
irris wound on a soft "numbero of turris
iron ring. When it is connected as shown, atate d
of which is 18 of:
(1).. the direction of currents.
. in both colls, and
(at)
the po
polazi1
ities at A and B. (iii)Rearrange the wiring so
aa to. magnetise the Iron making A the aouth and B the north.
(iv) If another so-Et iron her
is put inside the ring, :atate the polarities at
C and D in both cases, (1) and (iii)
2. (a) The diagram below show how
a light th ball behaves when a charged positive rod 18 brought near it. Mark the dis tribution of chages and explain
in each case:
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年金助成絕
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(b). Draw a diagram of a gold- leaf electroscope. Explain how it could be positively charged by the process of induction. (c) ▲ negatively chargea sphere in lowered into an empty copper loe-pail which stands on the cap of a
a gold-leat alectroscope It is then withdrawn as shown in diagrams, Mark on them the distribution of charges on the sphere, the pail and the elec troacope at: each: atep, Show how the gold-leef behaves, and give a conclusion from your obeervation
TT
化學科(十八)陳湛杰,
CHEMISTRY (#18)Q),
Bolutione for, Chemistry (#17)
12 Matter ia composed of molecules, each molecule being. at some die- tance from the other. Consequently the ·moleculea of one substance may be to fit themselves into the space between the molecules of another subatanne. The system that results cross dispersion of both substances in a mixture is called e solution of the two substances. Furthermore, a true sou
a true solution must: in which the
ch the components are of homogenous molecular in a state of dispersion without chemical combi- nation, for otherwise the combinat- ion would produce a compound and rtot
mixture. Hot just
Since matter can exist in either of three etates Bolid liquid and
and gas, several classes of homogenous dispersiona are ponsible. However, the common cases inevitably involve at least one liquid was one of the
componente of a solution.
B
When a solid solute is added: to a solvent and the mixture stirred the solid disappears, 1.8
i.e. dissolves. However, if additional amounts of solute
added: is continuously "eventhially the added solid wiin aimply fall to the bottom of the vessel without dissolving.
Thus
the condition for maximum amount of
solution has reached for
solute
The
solution is
that temperature. now baturated" wi Ealyst inctedw with respect to the
solutė,
日四十月三年五七九一层公年四十六國民華中育教儒茜
A
At
A supersaturated solution is one which contains more solute than 18 present in a saturated solution
Such a under similar condition. solution is also unstable since i詮 any solid solute is added, it will bring about a rap process of
rapid
arystallization, depositing the
amount of solute (over that. of a saturated solution),
dotting the solubility of
However, the side reaction to give diethyl ether (0,1), is also important, so that this is not, a good method for ethylane.. (11.1) from vicinal dihalides Thesa are compound in which two halogen atoms are aituated on adjacent positions in the carbon chain, halogen atoms can be eliminated simultaneously by treatment with a bivalent metal e.g. 2ime
potassium nitrate in water at 20-¤< - > > = <
the following procedure may be.
saturated solution is prepared at a higher. taw
temperature' ·with constant:
Br Br
The
although vicini dihalides are too expensive to be of use in synthesist stirring under the of alkenes, the reactions, solid solute. Then solution is frequently employed in purication allowed to cool slowly and the.
Oof ethylenic compounds. temperature is carefully monitored.
a quantity of the satursted.
OH Br-CH, Br solution is transfered by a pipetta
orating dish
to a
Preweighed evention is now
and reweighed.
carefully
aried and
and the quantity of
solute reweighed, The
difference of the two weights gave: the amount of water present in the
aample, the difference of the second weighing with the weight of the
CH2=CH2:
CH2=CH
Br.
The structure fer ethylene based on the Kekule theory is that two valences of each carbon atom are utilized to form a double bond an The molecular.
be:
ethylenic Linksameter. Formula
· has been determined to based on elemental analysis
evaporating dish gave the amount of Demolecular weight determinations
The
solute present in the sample. solubility can then be exprosted es grams of solute per 100gm of water 2. In the/laboratory; ethylene may: be prepared for ethyl alcohol, lethyl halides ar athylene-dihaiiden
most. convenient sources However alcohol is the cheapest and
This is the moat (1) from alcohol
The hydroxyl grous generate method. is an active function. Conversion into an alkene requires simultane- que elimination of the hydroxyi group with a hydrogen from an adjacent carbon atom.«
4.0
Thus it contains two atoms of hydrogen less than that of ethane, and the only way to Batisfy the totzecovalenoy of carbon atoms, dòuble bond must be involved.
H
It might be suggested that the following structures may be poast.
ble,
H
In the first case each carbon atom contains a single unpaired electron in the second case one carbon ato
atom contains two unpaired electrons... However, both formulas are unaccep- The either oatalytic of chemical. To table because. free udioals (ive.
containing
unpair
ired
Practical methods of dehydration
catalytic dehydration, alcohol vapour is passed through a tube. Packed with coarse granules of alumina and maintained at a temp- erature of 350-400°C by electrica heating Chemical dehydration are oazzled out:at Lowe temperatures. sthylene may be proluced from a nixture of ethyl alcohol and Heulphuric acid heated at 170°C. The reaction involves an initial forma- tion of ethyl sulphuric acid foll- Howed by decomposition to ethylene.
~HO
CH CH2O5000
H-C-C-H
H ̈050,03)
1700
www.those
Stavecies
are extremely reactive Fan Setons)
only have a transient existence According to the electronic theor the the
of two double bond consists
The pairs of shared electrons. single
bond serves to provide a firm link between the carbon atoms. The presence of an extm bond provides latent combining capacity: (the characteristic addition reactions of ethylene).. QUESTIONS FOR NEXT WERK DA
a
1. How would you treat the following cixtures in order to obtain the firat substance in each ca
copper and zinc
b. oxygen and dinitrogen tétroxide
nitrogen and carbon dioxide HOSO OH d. cono, nitric acid and conc
A saturated solution is one in, which an equilibrium is reached for the undissolved solute and solute in solution. This implies that the Frocess of diesolution is occurring
(11) from alhyl halides.. of at the same rate as the process alkyl Ballde ie treated with a basi
ystallization:
Bolution in: one in": An unsature which the sciute in the salvent.in. less than the maximun (equilibrium)
tration attainable at that concentr
Bolute temperature. The amount of may vary from a mere trace to a concentration just less than that of a saturated solution.
saturated solution is unstable since if solid solute is added a process of dissolution will take placeN without a process of orystallization.
的出滿:
打
When an
reagont the elments of hydrogen halide from adjacent carbon atoma may be removed, thus introducing a double bond "
>_q<+ Base → >C=C<+ Salt + Hol
an alcoholic solution of potassium. hydroxide is often used for this 【 reaction. Theoretically ethylene
bay be prepared form ethyl bromide:
sulphuric
acid
8. audium carbonate and caldium.
carbonate sodium bromide: and ammonium bromide
2. In 1962 it was discovered that at 400°0 gaseous xenon tetra fluoride (Xery) reacts with hydzogm to fom xenon Tand ganeous hydrogen fluoride. Assuming constant
the volumes of xenon and hydrogen pressure and temperature, calculate fluoride produced if 3.8-litre of xenon tetra fluoride reacts with CH_CH BX + KOH&CH=CH+HBx+HC, excess hydrogen at 400°C.
構機十七助援欵機金益公 幼老弱貧顧照元萬百四
康復殘傷置安元萬百二
年青導輔育教療醫餘其 吉
政府古千慈
費補助,但
政府不可能
機
○千欸民之利擔由五十
一級舞所息贍其
長篇的向除藎馨
千]
費明搬過個土
金年七民慨:
間費
除指派公司內高級人員
任
策隔外更有公司
响應支持捐公益金 反應熱烈募捐方法多種
·常
出儐變得費
「好一大筆記。
四至七五年 一九七形式千種百類 工廠僱員的捐款亦數目可觀,雖然是一元五元的攝獄,但演聚起來,便有同,用捐欸個封的“用 十個之深, 席冯子給太太。旁立(左》露商額及蔬來铙營處 高級行政助理林桂案,右爲盈書處助理采利秘書 11),代表將兽揪送交公益金募委員會小組主 慎計點,才可以令公益金的意泰和工作更深入民間,為贏大市民所認識。,用特別晚會,抽斃。 痒,因爲有些小型的公 公益金特别竂爾倔員募翁計劃,因為全港僱員人教案多,只有通過這一表格,白薪金逐月扣除 一定代表公司的熟心程 尤重儉員募捐、步行、和特別驚活動外,來自各個公司、機構、,而撒激形式亦各有不签金者仍然含數線七十 迷,公益念 籌募第Ë能開以來公司一途際路,還是行夢最樂一戰,但可能個人攢敗數
本年度公然金無寡運動,除了商行的郭默,個人個真的捎歇卽粉至香來,將偏動赛得娄持公 自從十一月中旬, 百顆,不勝枚舉,而殊 數字方面也許並不可
公益金油箱的,用树捌 多間公司,數字绣术
「獄之相同數目,以 然有許多公亲假期,
轍,所以月來反應至 熱烈,在二月份內,唯
字幟欸司
退,歡
熊面人有
人許少小的
數:
·酒-漁是處屁實聯誼會主席李如若太太(右,字很高。
真太將素
秘營觚
金撥作他信
四五九間公司僱員
一。公司方面亦十分 捐運動方面多所扶 僱員做事。在祖織赛
多元,距離目標尚有一百六十多萬元始得以完成
的工作將會因爲經史短缺而停頓。. 警疑,有多有少,合計選取假九百四十五萬1千
出便應依靠公益金向外界統一對導,否竄· 直至目前爲止,各界熱心人士推助公益金的
「對的歡迎,如果市民能够羣策力,集肝自可成
· 措助公益金善欸,郎使是一元殘角,也惠絕
一發敫二百萬三千元 张画一百二十九露三千元..
:(一)「照顧及安置高差」的機構十一間
·二張,做歎三百九十二萬三千元
(三)「照顧老人、家庭及兒童服務」接布
四十七萬元:
绿統霸共三十篇文, (七)「社團及社會福利計劃」機構四間
一百四十四萬二千五百元 (五)「青年喃導」機構十四間:發崴精共
大步行操歇的舊是,亦請平日儘快收妥善,是 一萬行委員會,一再呼鐵各界樂,尤其參加
一百六十八萬五千元...............
由於帶欸糖求股风,公茶金狮赛季片會及百
《六「覺車救J機柄九闖I譲致
(四)「多方面服務」的機構五間-最欸額
二
捐喪始萬力
議
生力啤捐二萬五 啹喀兵也來援手
截至收欸日期 三月十二日
$9.580.274.66
著璈二萬五千元撥捐公益金,造福實因。生力啤酒廠支持公益金,並非自 生力啤酒廠有限公司王岩泉先生,日昨亦行事不甘後人,代表公司將
中外人士公司行善不分畛域
利通
士会支極
的及餐
已收善欵總額
義演晚會籍公金 北角成人教康中心 群策群力盼其它中心响應
城傾國傾片鉅氏邵
金益公开映首日廿
禮主場蒞將價伉督港
·泰戲院事行。發 出日下午七時半,在 慈藩首演在三月 敦酒畲。..... 捷 水灣酒店亦嵛尤 剪綵粒並欣賞短片。
士及夫人角時將主教
亦已成立,委員出錢出力,務合首演能多無得着 ;周舞佛斗大盛大越首演,一個排他大青
銘牌一空,樓下只餘少量的心要做可得。 * 由於「俶傾城一般片當前,三百元的兵平日 計座超等三百元,樓下後座二十元,前座十分
一千五百餘人,B間之一劉康樂活動,參加人數 | 北角成人教育樂中心,為所屬十四個中心之一劍飂鋒治生、陳麗玲女士、陳女張先生、繪世 。誠中心自去年九月開始迄今,已擁有鞋册 先生、周文軒夫人、周患夫人,在立橫夫人、
·若被教育司要成人教育部主辦之北角英皇獷款!造陽忱苦。大會主席為沈諾夫人,类具包括
謝宜响顯,特於三月六日在該中心嗪其暴行中憑 富蘭宙夫人、漢姊夫人、唐翔千夫人、湯子和 近該中心會及疏於公益金對社會帮助茜大, 畫出、笋紹榮夫人、李嘉猷夫人、文洪磋先生。
·費嘉攜夫人、馮景禧夫人、林秀操夫人、书仲賢
心肚
鵲中心歌錫建、黃耀戴兩位主任、成人教育部随 。該晚共得捐歎二千二百五十七分三角五分,由 「四百餘人,即場認捐事號民主民作品,甚爲散烈 夫人等。 歷晚到出公司者除成改組部份長官外,雲夫人、董惠路夫人、健平小姐、姐夫人、赫信
接下少量的戲票,可直接向公益金告士打
全區、中小導而石壯樂、及會嘉代表類愛升、陳行七二四密,重括二金為五五门前。
mammMmm mm
頭
觀葉祖囊烁速四十河,他算明四十一元二] 官立上午是说一百二十分, 角,趙商共四十二元五角,張老四十五R,
一百十元,謙、魚、黑等一千二,
·名氏四十八元,陳備新四十九分二角 她與四十六元二角,赛大生四十六元四角,無 - 李静就四十五分七萬·吳佩一百三十九宕二月 天宙一百四十元, 苏赛四十五分六角
- 湯 質葉明一百五十元,一百五十R
惠子,秦家辣,劉志超,蘇式,馬精利,
唐山佛驶學校大院 催席嘉校十二元,楊秀惠十五元.
|清公益金。銓法外籍人士的慕心,自此亦可見一斑,正岛行并不分季敏的 輋教改揖作啹喀兵福利金及尼泊爾德機場票外,並發取其中四千五百元, 名氏,效力俗,何岳標,直未數,余明、茲烧,第枝光·梁惠圖·筆森全,蔡超、赛富、一刀,石硖尾官立上午小體教職員一百七十六 ,陳君!七八老人,而宅,無名氏:李根,蘇州李迁往,李寶炁,劉宅,方钻款,無名氏-筲- 對花用勾械样幻小量共一百八十元。
以下推五元,蘇宅,陳雜果:無名氏:
灼鸪 - 伍公里,要发就,展專屬-李來,張惠 婆·弟氏、诚北洪,李【爆+煮永祥,郭阻膩,對康、費用演,崔先生,李陳奎娜,本野菇: R-什天第一百八十旡 - 麥稙培植生群植保 名氏,焦女士,川段發绎,黃嫌號,杜棠- 瑞,劉伙,余先生,鄭籲,傅先生“本售: 無名氏一百六十八浒四角,邱志二百七十 -以下拑二十元:李宅,吳永澤、李宅,無吳爾生,歐富華,割榮,無名氏,慣照- 名氏,何,文學, 無名氏,
.以下摆五十元;黄氏‧羅炳照,摩斯托,
以下折十元-鄧金容,馮客,余老人,無
此外,漁農雄同度 #熱賣九百一十五。 當中, :各查自己一分力量,進步行,歟倫在收集 啟員,响语公基金需6 再接再度、再出動九 | 處、及來綁營處三層 八百一十元。該會會員 漁是處、測類統營一果人人落力,需因被新
·潘事不怕多做,
港島區公益步行、出長點心理實錯件。 一直會十五人,又參加警齊下,集成裘
募捐步行籌善款
漁農處雙管齊下_
代收公益金些星的卅一間銀行成其分行。”伍第二十五元,吳志猲二十大元 六角格我蝣上午中一F二十
十四元,梁永芳二十四元,唐冠希 六角五分 過二十二元,月 角·珠海學院工實警理il.j 敬请二十元八角,林玉二十元以 二十元:裘補給唐浩然二十元,第 其二十元,丁日組,丁派給了他活 站免杨家言二十元+同坤风燕
武伍十
冷無振林招
芭永二路
源源
一、唐,林,明十八元蹄二月)
元培例车 R
李明
根比
香港公益金
善長芳名錄
李禾青美一百六十殿,無名氏一百六十八R 佛教大光美果校一百五十四·教京精舍林 美国一百五十元,讓明为一百五十三元五角,
「後合一照,左起公益董皮努檢, 誼會 ~南讓你說傷救世育聯誼實步行物交
百七十七元,長洲買惠公立學揆二百九十元 ... .官立下午揆二百二十分,其扺粹二· 另,朱卓立董少清二百知,新民 決公司二百元,警紹培會導檗二百 森宅及富共二臂R·英商粉
麥氏,何家銘,里- - 名 史弟-語値年,實天宙-潘小挺,
·天志榮 楊志江-張存,以
凌疑,兼同,買獎生,盧志明,杜
以下二百和 - 區略,正宗,雨林!
·林冰:陳玉 龍特,陳秀美,孤傲民,葛宅,當名,關淑文 锌七十元,加山逢育部七十八分,戒才與八十四十元,兼本賞四百分,鼎宅四百元,富豪, 郭常,無名氏,江再興,畫名,備有课* 廉,数岸大十元四角,黃哲明六十一为六角,遮芙濱交機漢來橫三百點,小館[][
·無名氏,林炳森,蛋皮,導,李伯特 十元:文五十四元四角,英五十八元,潘女·举高梅, :以下「百宕:苦中。高葛天,有名氏,十石,微界赛基校八百六十九旡 鳥,
英賣事吳寶明五十元,吳感實英陳麗五 篪失落二百九十四年 照五百元,附中五百元,直来女子小歇八百,
九元二角。' 三十二元,徐鐡文三十七元八角,一歌姬三十·江小額,安泰安天公司,潮州公會。...
∴盤底祥三十一元,黃榮三十二分: 陳先生,老河鳥,素玉魚;何宅: 歆年,太平。
:以下梢四十分-寮塔·秋女士i陳瀚
五洲大
智一百了,朱五妹馬箭術費長拜一百元-沢 五萬元,保華建素有裝公司五萬元,孫棄看你 欺锦荣霞德如蒙少为一百元,仰高蘇寶安人縣(崇国)有限公司二籠分,公程慈善社
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色
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出「行」允文允 欸善元多萬篝行步
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費生的一切,現在只 良机-西太后掌政所
·家耳熱能詳的清光球
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