三月一年七八九一层公年六十七國民中育教育體
報日僑華 六期星
|直四第張三第日四初月二十年寅丙夏
WAH KIU YAT PO
加賽
體
育
|王席方德稿 等 ,並祝各人財運亨通,新年快樂,氣氛洋溢。參加觀禮之毀估計有,新界會長劉漢襲水上安全
·金錢與魯賽健兒。財神爺穿上妝金服,冠冕輝遼、笑口盈盈,與各參賽人員及遊客握手女 「花簇「翮商」波较之金炖設計非常沿賞。朶親自與世主席伊同財神爺(雞雞邦J派發幸運. 一使大會紀律進行再非常順利。拯總會長陳景福在熱烈袋聲中主持頒獎儀式,梨對于蒐年如意。”
·大会主席奈錦淘絕早親臨安排比賽事宜,來借問賽務主任梁摰康作各項佈及安全措施,
泳人士得以安全抵達終點。此表揚獲得全場鼓掌。
·在儀式中,冬泳的幹事素與獲頒投金星秀摸彩,
一日後到該會市區辦事處免費領取。地黏為灣仔軒尼詩道二五一批十字樓。 本年度審賽及詠畢全程者,一律將獲贈一情敵之熨金紀念股獸,以示隆重。各員可於三月
年又是他們成功的一年。這令到樂;加無限的路線,ega夜監工修理破璧之防被毙,使冬
太,渠知道他們十一年都未有間斷地參加此項賽事,而他們一樣的精神突交,與塞流搏鬥,令 |認爲合方舉辦國際元旦冬泳錦標賽已歷十一寒,在此次比賽當中,來認識後面普及相熟的朗 ;而每年參賽者税有加,相信參與多詠之人士已漸潮感覺到暹乐最有益身心之活動,陳會長 鼓勵冬际参加者之無畏精神,並指出一年四李游泳至足加强健康,並強調今崴已是第十一週年 頒獎儀式中, 首由大會主席幸錦初報告筹偉經過,並致謝陳鼾福會長選出幸運金餞,以
及東方冬泳會之陳丹鳳分獲次席及季軍,時間爲七分三十秒六 而 盍 - 成姿優異。而女子組亦豉爭激烈。結果南山游泳會之藻美蘭榮膺冠軍。與方多踩會之符梅 ,鼓咚之十公尺前進游泳會之葉賀民越游越快,卒以五分五十七秒二加獲案頭,奪得不仅日報 *) -KKE(ERGER ) · KESH(ER*K*) SBAC SHAKU -#692 「各食一開即以超速度搏殺,直趨終點。但兒窗花四恋,幾屐烈。男子組之業促民一助進游泳. 六百多公尺之賽程瓶是中距離之游泳競技,但因爲寒流冰冷之關系,濂來的確吃力,所以
「院除,聖公會聖十宇架堂社會服務中心,游泳會,菩灣拯用命及智健冬泳會等 灣泳聯,澳門冬泳會,荔枝角拯協會,浸會學院拯瀾會,工人俱樂部,雅麗珊爾会,民生書 我救生會,東華三院林百欣青年中心,南山游泳金,老中青说泳會,銀錢選長光泳會,深水 成人教育中心,勞校控友會,香港救生員訓練中心,新世紀拯爾會,傷殘人士體育協會,菲要 「會,黃大仙社區中心組,金獅游泳學會,巨流秕,新風拯會,聖瑪加利攵杏院,香港仔 拯學會-點在游泳會,香港發療輔助隊,士汶坯剪會,東方冬泳命,泳请游泳合,先簽拯溺 香港拯總會冬泳團,香港拯滿總會女子部,金江振爾會,工值冬泳團,縠誌社,魔鬼魚
使賽事倍形無關;參加之社團學校計有: 在發起者的之熱烈鼓掌下,大大增加了運動員之勇氣與鬥志。 遥次參賽者逾千名,盛况空前,統計有四弋社團像加,包括澳門港九及新界 離島之精英, 氣清,日麗風和,正是大地回春,-
滿新年氣息。那清澈的海水,仍然冰凍得非常有害。各人 年度首大水上活動、此乃香港拯總會華僑日報第十一屆國際元旦各樣鐡良群。是日天朗 (特)前天八七年元旦、淺水灣游人如蝮·盈萬市民都趁著新春例假蒞臨淺水灣參觀本
華僑日報盃元旦冬泳大賽
逾千健兒參加
葉賀民陳美蘭分膺男女冠軍人土日
男子組
第十一屆華僑日報盃元多泳錦標賽成績表
女子組
季軍:黃偉豪
亞軍:英素譯.
冠軍:葉費民
【東方冬泳會心
“(勵進游泳會 ]
:五分五十七秒二
(東方多泳會)
幸運組
季軍:陳丹鳳
·亞軍:符梅
冠軍:陳美蘭:
風梅蘭
CERVEC).
(BIRKE)
六分五十九秒
(東方冬泳會)
亞軍:盎巨南
冠軍:梁 華
(深水灣泳聯)
八分五十秒
〔總冬泳會】
季軍:蔡金水
(*****)
「總冬泳組
九分零五秒
冠軍:易海榮
澳門特別組
季軍:許浩章
亞軍:蔡金水
·冠军:巨南
十一届元旦冬泳錦標大奏中致詞。
香港拯溺總會會長陳景福(上)及大主席卷鑣湯(下)在第
「參加第八屆世界跆拳道大賽
今明伊舘選拔
·香港跆罕道協會爲 育館舉行。
·進行集凯,該會今次之行複賽,觀眾可免費人 及市政局贊助,今、明舉行,門券十元,在大克委員會會長沙理 | 兩日在灣仔伊利沙伯體|會堂,香港體育館,太 韓國駐港領事館官員等, 遴選賽,由康樂鬋脊局 導,决賽則於當晚七時,業餘體育協會妩奥林匹 特隊選抜賽選好手 明(四)日上午九進 薫香港的な遺協 泰像參加本年九月在西,參風此次選拔賽之,則晚決賽,優勝獎 今晚七時初賽,明複竇晚上决寳 馬坤香港
元,因爲他們獲獎高舉獎盃示
#*#***! KK - HEK(28) KEKE
〔南山分别在男、女子畫中拾
:第十一屆華僑日報藎元且多 空做及伊利沙伯體育館 主持頒發優勝獎品。
今後行及
泳理槳蕭及开
達士堤夜
襲得,藍以予金霸
裴以使工表幹星景
利港
- VAR HALDAS DE SA MU BUREKE(ESE)ESKURACHOR
女子組(下)各優勝 合照
1987中學會考 試題預習專欄
物理(十五)
明德出版社
MILE & DALE PRESS
Revision Exercises
for
Cert. Exam. (1987).
PHYSICS (15)
4.9 Machine
A machine is a
device by means of which a force (called effort) applied at one point can be used to overcome another force (called load) at some other point.
The force which is : applied to the machine. is called the effort (E) and the force
for an ideal machine, no energy is wasted, the efficiengy is 100%
AV.B. and thus M.AU.
Note: 1. The V.R. can be“
determined by
considering the
geometry or
arrangement of
the machine but
the M.A can be
found by experi-
ments only, or
from the value of V.R. and effici- eucy.
Practically; M.A.< V.BA.. The V.R. of a compound machine (a combination of two or more simple machines) is the product of the V.R.of the individual simple machines..
Some common simple. machinas: (A) Lever
exerted by the machine
[V.R.
is called the load (L)
The mechanical
Effort arm (E) Load arm (L)
machine is defined as
to the effort.
advantage (M.A.)of a (B) Inclined plane
the ratio of the load
H.A. -
The velocity ratio (V.R.) of a machine in defined as the ratio of the dietsnce noved by the effort (d.) to the distance moved by the load (d) in the
the
same tike
V.R.
The efficiency(c) of machine is the ratio of useful work put out from the machine to the work put into the machine.
* Useful output100%
Work input
31-weight
V.B.
#9
(C) Single pulley
(1) fixed pulley
(ii) Movable pulley
(D) Block and Tackle
or
Tefal output power 100%
Input power:
For a perfect. machine, e-1(1.0. 100%). In order words
the lover (movable) block,
Load
weight of the
efficiency
block 72x10
720 N
AMA.
The efficiency in smaller then 1 due to the effect of friction, veight of". pulleys and weight of the string. As the load increases, the effect of the above factors becomes. comparatively small, therefore the efficiency is much smaller than unity. for small load and tends! to 100% at great load. (E) Screw jack
V.R
221
(P) Wheel and axle
G
V.1.
240 N
(AUB)
(b) Work done by the
effort in raising the load 2 m
Ed
-E-(d,ZV.R.)
-240x(2x4) -1920J
Work wasted
= 1920x{1-75%)
̈ (Work done in raising
the lower block 2n)H (work done against
friction)
- (vaight of the lover block x 2m) + (work
done againat friction)
(140x2) + (work done
against friction)
Workdone against friction
➡ 480-(140x2)
200, F
Example 2
As shown in the figure,
a compound machine.
consists of a 30 inclined
(G) Simple hydraulic press plane and a viodines. The
V.R.
Example 1 M
Load
area
A pulley system consisting of 2 fixed and 2 movable pulley is used to raise a 72 kg lönd as shown in the figure. The efficiency of the system 18: 75 %. AN (a) Find the esfort
required to raise the weight steadily." (b) If the movable pulley
block weights 150N, find the work done against friction only in raising the lond 20.
radins of the cylindrical drum r ís 0.2 . The radius of the handle R is 1.2 m.
群
30°
(a) Find the V.R. of the
machine. (b) If a man has to exert
an effort of 201 to the handle so as to pull the block of mass n - 18kg up the inclined plane steadily find the efficiency of the machine. (e) In addition, if the,
block mover 20 m along the incline, in 30s, find the power wasted due to friction.
(Take & *10
Solution:"
-2
(a) V.R. of the machine
(V.R. of the inclined plane)x(V.R. of the windlass)
ein
(b) M.A
VORI
70 kg
=
wherein is the number of stringa supporting
Solutions (a) V.B.
MA
V.R. 75%
(18)(10)
efficiency.
MA V.R.
- x 100%
- 100% 75%
(c) The vertical distance
travelled by the block
2081130 1,0m
(l)
The displacement of the the effort d_»d, XV.R.
(Note:
E
-(10)x(12) -120m
*20xVB.)
Work done by the effort in noving the block for 20 m. (ie. work done by E in raising the blck through a vertical height 10m)
Erdg
➡20x120
2400 J,
Work done due to
friction NA
- 2400x(1-75%)
= 600 J
Power wasted due to
friction
600
30:
20 W
(Ans,)
經濟(十五)
明遇出版社
MILL & DALE PRESS
Revision Exercises
for
Cert. Exam. (1987)
ECONOMIC (15)
Population
1. Factors affecting the size of population
There are a number of factors affecting the Bize of population of a country..
A group of individuals living in a nation makes up a population of the country. A population; is always changing, depending on the rate at which its individus 1 members reproduce, die or migrate. In other words, the rate of birth rate of death, and rate of migration are the major factors. determining the size: of a nation's
population. They are: described in details na follows (a)Birth rate: The number of live births per 1000 population in a year. A country vì th high birth rate increases ita population size. However, birth rate i affected by the food
supply
and the
living environment of the place where they are aituated. A country having sufficient supply of food, natural
resources, fresh air "und" clean water, aud
also with gand
economic achievement and advanced technical skills usually tends to have a higher birth rate, since the environment is favorable enough for the reproduction of human beings. However, is some under developed countries, the birth rates are high mainly because an increasing population size can supply more labour force for their production activities, as long as they are labour-intensive.
(b)Death rate: The number
of deaths per 1000 population in a year. The death rate of a country depends on whether it can introduce modern adminstration
improving law and order.
and eliminating local warfare. Also, the
introduction of modern transport
communication, and distribution reduces local famines e Furthermore, a country introducing public health measures... controlling disease can reduce the death
(c)Net migration rate; In
each year, there are some persons moving into a country from another country, and also some persons. moving out of à country to live in another country. The former is called innigration, and the latter is known as emigration, The balance of migration; the difference between immigration and: emigration, will add to the size of population of the country.
However, the balance. of migration does not affect the total population of the world as a whole, Strict immigration lave prevent people move freely from one country to another."
In this case, the size of population of a country is largely determined by the":" death rate and birth
rate,
To
conclude, the
size of a country's population is a
combined result of the three rates described: above. The size of population can
become larger as the birth rate is greater: than the death rate, while the nigration is held constant. II.Effects of population
change a
* The rapid growth of
population has posed many problems on the world as a whole. They are described as follove: M
(a)The problem of food:
An increasing population demands for higher food production. On the.. other hand, the quality of food and ita nutritional value are both important to e country of rising. living atandards. Thus there, may exist a situation in which food is sufficiently: supplied in one part of the world while people are starving elsewhere. P (b)The environment
Population, growth is more or less related to the deterioration of environment quality, such as air and water pollution, depletion of natural resources, disposal of waste materials.. It makes the solutions of environment problems more difficult, ⠀ (c)Social problems: An
increasing population demanda for more social services, ranging from education and housing, medical and health, social wolfare, to law and order. Besides, the: / concentration of people in urban areas makes urban planning and administration complex and difficult. (d)Panily health; AW
family having many...... children may adversely affect the relation in the family, educational
opportunities provided. to the children, and also parental care. In turn, these will
affect the mental, physical and psychological, development of a child. A family, of large size usually han unsatisfactory family relationships and even
a deterioration of family life..
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