1979-06-09 — Page 30

日九月六年九七九一瑟公年八十六國民華中育教儁華

拓印出刊之用。 有各况,以便日後汜條製作技巧及材料用作 玻寨,並須填上秪籍所,機對生,創作意念, :參股作品必須附上,而氏作品將以造型 乍街香港最大銀行杻下)及先施公司索取。 : 良敦人表示 及教育代表組成 Bower

辦合協奏童部・司公施先,報日佛華

展計設具玩年少青港香 出發報海則章簽標展 參 簽標出刊版本下剪可漏遺有如

取索施先及報本往可用夠不仍

無搞鹫(昨

辦儷者

青少年玩其

EWIN

·海報章鹿等

印件-平已

“分批寄出:

者,可往錄

SKORE

就樣有效。

BYAL

脊版刊印之

如有遺 TRIES

ORFØR

#80

先始公司及

KERNE

質二第張八第5日五十月五年未已歷夏

"WAH KIU YAT PO

報日僑華

姓名

地址:

性点

MOJA.

學校或職業

租别

作品名稱

編號:

香港青少年玩具設計展 燙傷款区

YOUTH CREATIVE EXHIBITION - TOYS.

(3,75x10)

張設計師,兒童心理事

,英術教育家,專業

一般計由著名,盤衆家

瓦設計師合約。. 東可能獲得一份專業記 加・海人除外! [專上學院成專案人士装

HEMERKKI

盘收件處。

頁

50%

第消尙

有

張刊教! 第在育

含外离僳準。

一殺百人文稱:任用 形式的玩具股旴,如玩 本月廿五起收件

|

CEKELEE - WR

參蕤作品貂於本年

NGE

HACHENMERS

六期星

期玩具均可一段,並有望,海中環先施大谍软件應

六月廿五至卅日送交善

-RENTRERET SA

收件處及新界元朗大

.發言人文舱:該展

「螲公開組特別歡迎就說

x (0.02) x (2x10′′) (d) Work done by the load

1979

中學會考試題預習專欄

附加數學科

1.5%

Density

建議參考資料(一)

明德出版社提供

10

HYSICS

SECTION A

MECHANICS

1(a)(i) extension of the spring

0.130.1m

8 x 103 kgn

(Ans)

(b)(1) As shown in the

force diagram

per second

4000 3x10

123

(Ans)

power developed by the by the man

1004

(111)

0.03 m

Apply Hook's Law

kx

the force exerted by

the spring on X

(e) Gil should be poured into the space surrounding the screw to reduce £riction.

SECTION B HEAT, LIGHT, SOUND

(b)(i) n

(3.3x1077)(1)(3600).

1.188 x 10-3

The mass of the copper

rod is reduced by

1.188 x 10"

(Ans)

(ii) The mass of the piece

of steel is increased

kg.

by 1,188 x 107

Remains unchanged.

(b)(4)

1=5m

(c) Apply n

¥

50x 10

(500) (0.03).

15 N

and WAVE MOTION

k(a)(1) B has a higher melting

tension in the spring

(ans).

point

Apply

alance T

(11) Let

upturu

ght of

1(10).

(ii) the resultant force

acting on X

15N

58

10N (to the right)

(ALS)

(111) Apply

ration of x

19

(iv) Apply

0.12-9,5x10

0.025N

(Ans

Apply I = dgv.

0.025

rates of heat

supplied to

A and B

time required for

A to melt

completely

time required for

E to melt

completely.

mass of A

mage of B.

specific latent

heat of A

(ADS)

specific latent

heat of B

(5) (2)

-1

10 ms (Ans)

velocity of X after

2 seconds

(b)(1) Take the direction to

the right as positive

itial momentum of the

system (2)+(10)

Final momentum of the

system

where v is the comman

velocity of X and Y

the impact.

By conservatior

linear momentum

(2)(10) (2

(d)(10)(1.5x10-6)

.667x101

(ii) Let W be the weight

of liquid X and the

beaker.

WE AN

Let R be the reaction

of the balance Son

the braker when Fis:

immersed complete

in X.

3.33ms

(Aus)

(0.12)+ (4)

(9.5x 10

44025%

(Ans)

the reading of S is then 4,025N

(iii) The reating

(Ans)

(ii) Average force exerted

on X by

rate of

hange

momentum of

12N

3(a) The work done by the man

(10)x [5x 2 (0.2)

(10

x2) (10x 2)

GOJ

0.2

The vertical heigh

200..

N

(Ans)

-66,7 N

The negati sign

indicates the force.

exerted on X is to the

left.

2(a)(i) 3.75 cm

raised is

5 x 1.5x10

= 7.5 x

10′′

The potential energy gained

(4000)x(7.5x1073)

(b)(1) The amount of

5(a

(Ans)

303

(c) Efficiency.

(ii) Micrometer screw gauge (tii) Nasg of p

Useful work done Work done by the effort

X

100%

x 10

Volume of P

30

X

heat required

(0.02)x (336000)

6720J

(Ans)

(ii) The amount of heat

supplied

(0.05)× (4200)

(20-0)

4200J

(Ans)

Since the result of. (i) is greater than the result of (ii),

therefore the final

temperature of the

mixture is 0′

(iv) It is because the ice

is not c

completely me

melted and the amount

of ice molted is not

known.

a convex lens

concave

In Figure 6,

the image is virtual.

In figure 7,

0.05 -

0.505m

50.5min (Ans)

the distance between

the lens and the film

is 50.5 aim

(ií) 1. Reduce the

Lens-to-film distance (i.e. reduce the

image distance), or

Reduce the distance

between the object..

and the lens,

6(a)(i) To produce circular

waves.

(ii) To reduce the velocity

the wave.

(b)(4)

shallow portion:

(ii) Stationary wave.

(c)(i) 2,5 cm behind the plane

reflecting surface.

dot vibrat

the path difference

13cm

x wavelength

it ia a destructis

interference.

SECTION

ELECTRICITY,

MAGNÉTISM

and

ATOMIC PHYSICS

electrons

the image is real

(ii) ions

the resistance

the electrolytic cell

90

(Aus)

(d) It is because the battery

has internal resistance

and part of the voltage

is used to drive the

current through the

internal resistance,

8(a)(i) Anti-clockwise (11) There will be

NO change.

(iii) The coil will turn in

clockwise direction

and anti-clockwise

direction alternately. and will finally rest

in the position where

its plane is

perpendicular to the magnetic field.

(b)(i) The lamp will flash

(ii) The lamp does not

light up when the switch remains closed.

(iii) The lamp will flash

If a c. power supply":

is used, the lamp

will light up in all

the above processes

9(a)(i) Alpha particle

(ii) Beta particle (iii) Beta particle

(iv) Alpha particle

(b)(1) R

negative particle

S proton

the original

particle (neutral)

It is because a force

is acting on a charged

particle when it is

moving in a magnetic

field.

(c) Mass of y

(1)2

(Ans)

Mass of Y

(Ans)

T I F EN

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