1979-10-23 — Page 36

翼四第滕九第日三初月九年未已腦

1980

ive. f(x)=x^-3x“-13x+15

2

WAH KIU YAT PO

報日僑

二期星

a2-2ab+b2 > 0

=(x-1)(x2-2x-15) =(x-1)(x+3)(x-5)

+2ab+b]

the other factors of

the expression are K+5。 x−5.

中學會考試題預習專欄

數學

(三)

Mathematic

明德出版社女長波提供資料 (3)

13. Given: PR is the diameter

and NRM is the tangent of the circle

Section 8.

Solution to Exercise 1

11. Given: ABCD is a

//gram

LADY/YDC, DY // BX

Tn prove:(a) △ABX = ACDY

(h) BXDY is a //gram (c) AABY

ABCY DC

To prove :

AD

C

Proof: (a) *. ABCD is a

//gram (given)

. ABCD AB//CD

(or); sides //gram)

BAX=/DCY

(alt /s AB//CD) DY//BX (given)

.*. [ABX=[YDC

(8 between 2 pairs

of // lines)

AABX = ACDY (A.S.A.)

·(h) DY=BX (curr sides = As)

BXDY is a //gram

(0)

(opp sides equal & //)

AABY AY △BCY YC

(same altitude )

LADY=/YDC (given) e(/bisector,

AY AD

YC DC

property)

AABY AD ABCY DC

12. Solution:

(a) a−3+2b=}

12

(subst)

5b+3ab-8-13-0 from (1), a-3-2b. Put (3) into (2)

(1)

:83

5b+3b(3-2b)-(3-26)2-13=0

5b2+9b-6b2-9+12b-4b2-13=0

(b)

562-21b+22x0 (5b-11)(b-2)-0

... b-11-0 or 2

bal

When be

0-3-2(2)=-

When b=2

1-3-2(2)=-1

the solution of the equation is

-}

11

fa=-1

or

b=2

X-1 is a factor of

f(x)=x3_3x2+px+15

f(1)w1-3+p+15=U

p=-13

洽近

驗

二版

黃心小車

PQ*PN-PR2

APUS and APMN are similar (c) QSMN is

cyclic

Proof:(a)"." PR is the

diameter

[PQN:=90° ([ in

(PRN=90°

gemicircle)

Tproperties of

tangent)

.*. PQ•PN=Pn2

(b) Similarly, PS-PM-PR2

i.e.

PQ PN PS PM

PQ PS

PM PN

LQPS=/MPN (common) APQS and APMN are

similar (ratio of 2 sides, inc.

(c) [PQS=(PMN (corr /s,

similar As) [PqS+/SQN=180° (adj £s

on st. line)

i.e. [PMN+/SQN=180°

QSMN in cyclic

(opp. 8 supp.)

14. Solution:

(a) Hadius of the

hemisphere

44

44cm

2 cm x 7cm

(a+b) 2 >

248b

log(a+b)">log4ab

210g(a+h)> 21og2+1oga

+logb

log(a+b)>19g2

+查(loge+logb)

log(a+b)-10g2

> (loga+logb)

ive. logan > b(loga+logb)

10. Solution:

Let x he the number of animals that he bought

1200(1+5%)

x-5

1200 6

-

X

1260 1200 6

x-5

+

1260x-1200(x-5)=6x(x-5)

2

60x+6000x6(x2-5x)

10x+1000-x2-5x

2

x-15x-1000=0

(x-40)(x+25)<0

x-40 or -25 (rejected)

the farmer bought

明德出版社魯榮家提供資料

PHYSICS (3)

|Exercise 2

Mechanica

(Take acceleration due to

gravity g m 10mg~2)

1. Two blocks of masses 10kg and 15kg are connected by

a light inextensible string which passes over a amooth fixed pulley. Initially, the 10kg-block resta on the floor aud the 15kg block is held 2u above. the floor as shown in figure 1. If the system is now released, (a) determine the accelera- tion of the /system, (b) find the tension in

the string,

日三廿月十年九七九一瑟公年八十六國民華中 育教僑

2. A pile-driver of mass 10kg

a height of

is raised to

12 and is allowed to fall on to a pile of mass 12kg. which is to be driven into

the ground.

(a) Find the velocity of

the pile driver as it strikes the pile.

(b) If the pile driver and the pile move together after impact, calculate their common velocity just after the impact. (c) If the pile then cumes to rest after penetra- ting 0.5m into the ground, calculate the average retarding force exerted by the ground on the pile.

5. Three blocks of masses

10kg, 20kg,and 30kg are connected by strings as

shown in figure 2. It is

then pulled to the right.

with a force F-600N.'

(a) If the horizontal floor

is frictionless, find

(i) the acceleration

.

of the system,

(ii) the tension in

each string.

(b) If the coefficient of

friction between the

30 kg 20%

horizontal Floor

figure 2

4. As shown in figure 3, a

load of mass 50kg is raised by means of a pulley

system. The efficiency of the pulley system is 40%.

Effort

figure 3

(a)(i) What is the uptimust

of water

on the cube,

(ai) Find the fraction

of the cube immersed,

(b) If oil of density

1_of -3 720kgm is poured onto the water until it just covered, (as shown in figure 5) how much does the cube rise? plastic

WATER

figure 4

OIL

plastic.

WATER

figure 5

數字推理練習五 英文字母的排列 選出下列各類的正確答案,如在它的下面 畫一橫線。

先看下面按次序排列的英文字母,然後 解答問題。

ABCDEFGHIJKL MNOPORS TUVWX YZ

下列第1至第10題序列最後一项的字母是付 麼,試把它應出來。

2. TSROP ?

AW

3. AZBZC

AX BZ CY DA ED

7, ZYYX W

PV 8.BABCB ?

來口

11. AGH|

12.ACCC

NRM is the tangent

1.ACEGI

40 animals.

AJ

BH CK

DF

EB

(mean proportainal)

1980

BV CM

DN EO

?

2

中學會考試題預習專欄

blucks and the floor

is 0.2, find

4. ADGJ M

?

物理

(三)

(i) the acceleration

of the system,

AP BN CO DL

EK

(ii) the tension in

each string.

5. GHGIG 7

AE 6.ABEFI

PC QD

BF

CK

DJ

EL

?

RJ

SH TG

FC500N

?

QU RT

SW TX

PE POI RH SO

TQ

9. L MNKP ?

PJ Q1 RH

SO

TQ

10. ZAYB X

?

PW QV RC

SD

TE

下列第11至第20題的五組字母中,有四組是 有一定關係的,試指出沒有關係的一組字母

BCEF

CJ KL

DABC

EX Y Z

BEEE

CYYY

DP PP

EUUV

13.AFEF

BMNM

COPO

DS TS

EXY,X

14. AY X W

BTS R

CFGH

DP ON 15. AEGG

ELKJ

BJLL

CQs S

DACC

EMNN

16. PBDF

SJLN

QWY Z

RACE

TMOQ

17. PABB SEFF

QGHH

RCDD

TIIJ

18. PIHI

QYZY

RKL K

SABA

TEFE

QOPQ

RGH1

SFED

TL MN

20.PACC

QCEE

RGHH

SB DD

TDFF

Oc QE 3)B

答

QA

OD

GR OS OP

0Q OR

OB

DE

箫

® A

@C

OT

P

S

車汽

79

欄專賣買

港

補體】

熊小

科

島

大 補

考生

溫補 預

預大 石蒜蚊

七美理國

下午楠小.

圆太一四大四三

(b) The volume of the vessel

-xx(7)+(7)2+(30-7)

-1898.6 cu.cm,"

(c) Slarit eige of the.cane

√232.72

cm = 24.04cm

Surface area of the vessel

•jx4x(7)x+x(7)(24.04)

-836.54 84.CM.

15. Solntion:

- •

(mb} ?>

20

全港九最大

補 汽車椅套總匯

專科 械

四九中獻

高興门

大

景式、黃色都通四十三

每套特價$48.80起

九路是水埗保安康30號地下

歐生

(e) find the velocity with

which the 15kg-block strikes the floor, (d)'find the time required

for the 15kg-block to reach the floor,

(e) find the maximum height

reached by the 10kg-block.

15kg

炒

figure 1

10 kg

Fiocr

(a) What is the velocity

ratio of the pulley system?

(b) Find the mechanical

advantage of the machine.

(e) Find the minimum effort

required to raise the load.

(d) if the effort applied

to the system is 600N, what sort of motion

will the load perform,

5. A plastic cube of side -3

10cm and density 900kgm” floats in water (density= -3) with the upper 1000kgm

face horizontal, (as shown

in figure 4)

606769 7373 73 73747475767677 78 7878

全新貨車 23

19. PABC

○午學鑒

預

碩

科

預

香港學生輔導中心教

180會考進修(青組:政府註冊社菌)

青本盤飾班今年會考成讜: CHEM 合格 196%PHY90.5%ENG.89.1%

拳各珉薪翼、十一月加酵新垢。名額有限,報名變潮。 報名:九難知道613號藟歡大厦3601日(按18字)*(大公司剛面、五月右上)

__()–311866 ( 1-2GINTZARVAS) :

全體團

任何F.4升F.6生及由怖老

會考優異英數

現在任何一天可幾月$60

·空氣調節,實歐籽油

小組形式鰭圖學生功長 星期一等五,每日二 小胸、太子道二五七

咖啡農樓上)

進〇由小七二

運

3:707036 5-704084 3-708019 5-705074

立信搬屋第一家

機慢運貨要提他

20 # 38

178-1617 1 677545 3 *720441

九補業

五种酒

有

繩收學 大同

小學補習 第一網中心

小學初中。會考预料

搬運公司

太子道二五七號(酵

農播上)

COFFEE-

邻

英數理科.

專科補習

弗糖

中學教師任轪

K四八丸大一

大專化學菁

保有成

H510435 H571246

七可小廠 洽

集

補精甲工

【補古

於數補

下門觀鳥科科大 渊小

送 港大畢業同學主辦

會場及高等也震英文退蹕學招收11月份新生

(另有露中四流酸之特別班)

一心中了

替化 下司習報名地址:海東街61號電發大廈

|洽名称胡四| 品

敏感博考試研警所抽生

會考英文數理 中學各級補習 大學入學試補習

陶製及灣大學繫飄會英文作者 |任教吳進293號22R(0)786278

(海洋戴贏打字橿中心内) 電話:(三〇七一八五

超漿翁养 搬

物中英

457883 457887

1400834

運

安委倫中中會

理文文

化生數

华表蒙大四大考

34

140元00

【學助量教 報日儒華

刊本報分類廣告

「豪華解睛 翁仁長善

撥請電話

5-221583