1980-11-11 — Page 24

華僑日報 All

DXLAX; DYLBC; DZLAB.

頁四第張六第 日四初月十年申庚歷夏

WAH KIU YAT PO

報日僑華

二期星

日一十月一十年〇八九一曆公年九十六團民華中

from the smooth

(1)(a)(g) (104)

(Tr3)(f) (6) (r)

wall of the

1981

3r

中學會考試題預習專欄

(b)

r = √3r

cylinder

weight of the ball reaction between the balls.

101 -

o (c) (2A)

(7)(d)(g) (10A)

Given: ABCD is

quad.

а

a cyclic

(0.5)(a)()(8A)

物理

Ans

i«e <DX€+ZDYC=180°

(Given)

明德出版社魯榮家提供資料

·PHYSICS (6)

W.E.IO.

(MILL & DALE PRESS LTD.)

Answers to Exercise 3.

1(a) Take the direction to the right as positive Initial momentum of the target

= (100) (-3).

-300kgms

Initial momentum of a

bullet

(0.01)(600)

6 kgms

Assume n bullets are

required to stop the motion of the target, the momentum of n bullet

6n kgms

Since the target stops finally, therefore,

the final momentum of

the system is zero,

6n-300 =

As shown in the figure,

the centre of mass of the combined body is G and is x cm from G2

Hence, moments of the weights of the cone and the hemisphere about G are equal in magnitude (− πr2n) († ) (6) ( 3h+ğr-x)

(rr3) (4) (5) (x)

-x)=2rx

h =

x)=2x

2

(ii) The system is in

stable equilibrium because the c.g. is

below 0.

(a) The direction of the

reaction from the smooth wall of the cylinder on the upper

ball is normal to

the wall and towards the centre of the ball.

(b) As shown in the

diagram,

BA

x (radius of the ball) 0.2m

BP (diameter of the

cylinder)-2x

(radius of the

ball) 2x0.15

0.1m

2x0.1

√BA?

數學 (六)

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Mathematics (6)

CP. Man

MILL & DALEEPRESS LTD.

Solution to exercise 2. Section B. 11.

Solution: (■) AB is the

diameter of

- LACB = 90° circle. .• ¿CAB+LCBA - 90°

£NCB+ZNBC2 = 90

- LCAB .NCB In AACN

EN

tan≤CAN

AN

In ACNB

tan NCB

NB

CN

CN NB

AN

CN

CN"

(c)

Area of square of side CN = a(12-4)

To prove; (a) <DYX = ZDBA

(b) X,Y,Z are collinear

Proof: (a) DXLAX, DY1BC

LDXC=ZDYC=90

D.,X,C,Y are concyclie

(opp a supp.

¿DYX=4DCX (48 in the same

ZDCX÷ZDBA

ZDYX=4DBA

segment)

(Ext. eyelic

(b) DZLAB (Given)

ZDZB-90

i.e #ZDZB÷<BYD=90***

‚D,Y,Z are concyclic

(Converse, Ls in

the same segment)

ZABD+ZZYD=180°

(opp. ́s cyclic

quad.)

(Subst.)

ZDYX+ZZYD=180* X,Y,Z are collinear (Adj.Ls supp

B

50

Ans-

(b) The energy lost

2(a)

during the impact

1(100) (3)2 + (0.01)

(600)2(50)

450 + 90000.

90450J

As shown in the figure,

and

are the tensions T Ang

2 in the string.

Let a be the acceleration of the 18kg-block, then the acceleration of the 8kg-block is 2a.

8(2a)

16a

T2 = 271

(1) (2)

sine

Since the balls care

in equilibrium,

Roine

(1.5)(10) 17.321

AN.NB

(b) Area of square of side

2

CN CN

AN NB 8q.cm

a(12-a) sq.cm

≈ 36~36+12a-a 8q.cm

36-(6-1)2 8q.cm

2

The max.area of square of side CN 36 sq.ca

12, Solution: Let $C be the

basic cost and V km/hr be the speed of the cable.

C+ky where k is a

68 +8)

constant.

770x+125k---. -(2) (2)-(1) 702 - 117k-

k = 6

Put ke6 into (1)

68-86 20

13. Solution: (a)

Given: ABGR, BCFG and CDEF

are squares

AGF (a) A.

EGA are similar

(b) 8+&+ß=90°

Proof: (a) Let x cm be the

length of the sides of the

squares.

+x cm=2xcm

(Pythagoras

Theorem)

No2

AGGE

GF

ZAGF÷ZEGA Common)

AGFA EGA

are similar (ratio

of 2 sides,

• Inc..).

(b) * =LGAE (Corr. ́s similar

60+LGAE

But B

(Ext.

ofA)

Let f density of

copper

Weight of the copper

cone

= (} #r2h)(Y) (E)

Weight of the copper

hemisphere

Since the centre of mass of the combined body is at

and the ments or

therefore, the wei

of the cone hemisphere

about C

are equal in

mani tude.

185-212 18a. ·(3)

Substitute (2) into (3),

186-212 = 18a

9ɛ-T2 = 9a

(4)

Substitute (1) into (4),

98-16a = 9a

25a = 96

(10)

Let d

3.6 ms. Ans

acceleration of the 18k-block is 3.6ms

and that of the block is 7.2 ms (b) T2 = 16(3.6)

(0) 12

= 57.61

115.2N

Ans

Ans

Hot N the ren Lon

#

density of water f = relative density of the wooden block

Upthrust on the block due to oil

(0.5) (the

where A is

cross-

coctional area of ube

Upthrust on the block due

to water

Weight of the wooden block

・本案之死者が一九五歳平(即死者),四疑者音神盪人県你及

心中區社南山礬慈府猛死的,可命逛過生

打死我煎包作,我約團

年週五慶明。者勿把有死無一

幕開會輋年嘉之卡海薇,

**

THE

人換足因 味榮食吸

......所炎不殘

引起為弦不同。 她與我才足够,以免再,他會認證 幼稚励。 文被告如何給予食物與,到華區,當時不以爲 人員到仲被告家,教導、高處跌落地上,因而受 先後永了排名驚整肌孫子說她就耍時,從露台 HTC-KOKEP STÆERHER 就讀,但秒杀了一個月

入院時位得北二磅|临本人訴讀到小學六年 當時她差不多到五歲,一行,亦是很易跌倒的, 她到瑪嘉烈醫院求诊,投,且她平時在家中步

·五日,小被告第二次點 她行需惡劣,而越她出

一九七八年二月十,被幼和的老覦

「增加了九磅、出院臨家見面部有报,向

「地至廿六磅,載入洗時,午六時放工返家財,宕

一天 八月九日,欣迎各界 留院了約一個月,最 他育引起低亦不良,她一樣激賞,並且在雄死亡態,城色比賽及象棋比

一 兒童得不足強支物,她,對她與其體子女一」欣賞會」。飛發還宇游 一,並對实被告示,凡」,但他與發行就無陵殿」「誆位逄瘀」,「影 燈,她因玉表不良所」般兒童歌,說話不離科 | 内居民同樂項目有: 一名赫雄邕治的醫生跳,欲女平時的智軾「嘉年寧會」,招待 時爲找基八個月大,死後十分傷心,他表 三十分,在中心聯合舉 最低經六發, 已經不袷無命,他開一十二)下午二代 ,泰之同年齋之兒車的,急救,一小時知迢女兒一套亞會,新九跟婚女岔 到站锬代育花十七磅各一午八時著瑪嘉烈醫院 基督教光年分,小蕉 老治长瘸袪宙營至發致九九九報整、於上「博:就會福利署,中

·莎伯影院求醫,根悅生」,推她亦無拉筋· 心服務

六日陕被送到伊索 全身低 一九七六年十一月女,已發覺我女〔死 死这是斛炎。 他起狀後即推酴五名子社會 社懋中心 ,在热烈悯院死亡,,當案發日上午六時南華(

PIERKEKHEZ CK | XVISSER,

(新 是兩名被告之次女,一,他本人在地盤做泥工慈月 七三年10月廿三日出生後,刚歲半及附個月为一船打

意 人共有四子一女,她,月薪一千五百元,雙慶年

勉行校

人士能盡。

春青好華年樣花

程前誤毒吸必何

慶祝五週

躲就鏃

#I-

(b) Let

5b+2c

2642

k

x+y=Z+Y+2;

7+8

22

8+9

X+Y=Z+Z

7:49

*

#

而且支

(Subst.) (properties

square)

Solution: Selling price

for 4 of the estate at

a gain of 20%, 83×240000x(1+20%)

$72000.

Selling price for - of

the estate at a loss of 15%.

$=x240000×(1-15%)

$81600

Total sale for the estate at a gain of 10%.

$240000×(1+10%) $264000.

The selling price of the remainder estate, $264000-$72000-681600.

$110400.

Gain percent of the remainder.

170500-240000x(1-1-3)

240000×(1————)

31.4%

100%

「本港新聞

涉嫌縱火謀殺小弟弟

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