1977-10-26 — Page 25

青教僑華頁一第張七第日四十月九年巳丁磨片 WAH KIU YAT PO

郭日僑華

育教僑華

In the figure, DC is a

diameter of the circle.

By using the cosine

formular, prove that

22 2

2 Zabe

2 in experiment was

set up

as shown below.

red ink solution

d=a+b+c

a

13.

學能推理練習專欄

智慧社主椒

bottle

test- tube

數學(四) 女長波

Mathematics

Exercise 2

Attempt All questions in Section A and any Six

questions in Section B.

Section A (Each question

carries 5 marks)..

1. If A+B+C=180" Simplify

COSACOSC+cos(A+B)cos(C+B). COSAsinC-sin(A+B)cos(C+B)

B:

In the figure, AB=AC=10cm

and the perpendicular from A to BC is 53 cm. Find 4BAC in degrees and in radians..

In the figure, DC is the diameter of a circle and AB is a chord parallel to

If ABAD, calculate ZBAD. (Geometry theorems need not be quoted when used.

In the figure, BY bisects ZABC and XY/BC, AB-8cm, BC-10cm. Calculate the

length of AX (Geometry theorem need not be quoted when used.)

Simplify

3× – , (x++4).

2

The 4th term of an arithmatical progression is 10 and the 8th term is 16. Find the 9th term. Sum of rain falls on the flat roof 264cm by 330cm. The water runs into, a cylindrical tank 84cm diameter. Find the

increase in depth of water in cm.

(Take T=24)

A mau in a train travelling at 30km/hr. notices that a train going in the opposite direction passes him in Vsec.

If the length of the train is 220m, find its speed.

Section B

9. If 3x-4y+7z=0 and 2x-y-2z-

Find xyz. llence, if

3 3

3x y +z 18 find the

values of x, y and z.

10.If 2, 3 and k are the roots

of the equation

3 2

2x+mx-13x+n=0, find. a,

n and k

11. In a triangle, the sines of the angles are in the ratio 4:5:6, and the side opposite the smallest angle is 20cm. Find

12.

(a) the lengths of the rner

other two sites.

(b) the area of the

triangle and

(c) the greatest angle in

the triangle.

·1-4.

In the figure AB//CD;

BCLCD. If AE-EF-BD prove that

(a) BE-BD

(b) <ADC BDC.

In the figure, PX bisects' ZQPR and PV bisects ZRPS. M is the mid-point of XY. (a) Show that P lies on

the circle diameter XY, (b) Hence or otherwise.

prove that

2 2

RY RX 4PM RM. 15.A 36f. cask contains 302.

of spirit and 6). of water. 12. a are drawn out and the cask is then filled up with spirit, 12 more litres are withdrawn and the cask is then filled up with water. What is the final. percentage of water in the cask?

16.890 is paid for a task.

which A can do in 3days of Shomreach, Bin days of 9hours each and C in 6days of 10hours each,

(a) Find the ratio of their

hourly pay.

(b) If Hand

C

were

together, what is the total amount they will earn în 10 hours?

(c) If A works alone, how long will it take him. to each $40?

生物

(四)

梁永華

BIOLOGY (4)

Unit Two: Respiration

TI Conventional Questions:

The following diagram

diagram represents a piece of apparatus at the end of an experiment.

flask

KOH soln

mérnina- ting seeds

Atm pressure:160%|

mercury

15 cm

e. What is, the hypothesis that this experimental set-up is endeavouring to verify?

b. low would you prepare a

control for this experi- ment:

c. The mercury rose

15.cm

at the end of this experi- ment. How would you explain its

d. What complication would. occur in this experiment

if the germination seeds. had begun to show green

Leaves?

Ans:

a. This experimental set-up.

is to verify the gaseous exchange during the 'res- piration of germinating sceds.

b. A control can be prepared by using a similar set-up with no seeds in the flask. c. The mercury, róse 15 cm at

the end of this experiment indicated that one-fifth of the air (i.e. oxygen) was consumed. (15/76 + 1/5 7

d. If the germinating seeds

had begin to show green leaves then the green leaves would take in carbon dioxide and gave off oxygen

during photosynthesia. This

would cause the experiment

to become complicated.

insect

Explain the purpose of this experimental set-up. b. What is the use of the

bottles?

c. What would you expect observe if the insect (i) is a dead one. (ii) is living but does

not move.

(iii) moves all the time. Explain it.

Ans:

a. The purpose of this experi-

mental set-up is to detect the ras-pressure changes i test-tube A and B. Tor instance, if the gas pres- sure in test-tube A incre- ∙ases (e.6. due to higher temperature) the red ink, solution will move towards test tube B

To prevent the disturbance produced by environmental temperature fluctuations on the system.

(i) Since the dead insect

no

effect on the

pressure in test-

A, the red ink solution remains in its position.

(ii) The insect resrires. The heat energy pro- duced leads to gas expansion in test-tube A. Thus the red ink sol:tion moves towards test-tube ...

(iii) The movement of the

insect increases, the. rate of respiration.

Frater not of ener- released canines the gas to expand more. Thus the red ink sola-

tion moves towards test

tube B much faster.

3.a. List the e

the differences between aerobic and

anaerobic respiration. b. Where does respiration

take place in the cell? Explain why respiration. is found in all living things?

Ans

Aerobic respiration: 1) oxygen is essential 2) nore energy is produced 3) carbon dioxide and

water are end products Anaerobic respiration: 1) oxygen is not necessary 2) less energy is produced 3) carbon dioxide and

alcohol(in plants) or lactic acid (in animals) are end products

b. Internal respiration takes place in the mitochondria,

c. All living things require

energy for their living

activities. They have to

obtain energy through

respiration.

地理李婉儀 黎仲豪

GEOGRAPHY (4)

Answer to Question 5:

The seasonal distribution of rainfall in Hong Kong ::

From the climatic graph, we can see that the rainfall in Hong Kong, with an annual total of about 2,000 - 2,500 m.h., does not distribute evenly. About 80% of he rain occurs in the summer months from May to September. A monthly total of over 250 m.m. in the summer rainy season is not uncommon. While in it is ralatively dry,

Bater,

The summer maximum of rainfall in Hong Kong can Partly be explained by the influence of monsoRDS..

Hong Kong lies in the Asian mon- soonal wind belt, in summer,

a low pressure belt is formed over Mongolia, while a high

日六廿月十年七七九一屦公年六十六國民華中

三期星 pressure belt is found over the sea. As a result, the winda blow inland from the

sea. They are therefore molet. and they bring heavy rain to

In winter, the Hong Kong. winds blow offshore because the low pressure over kongolia is by now replaced by a high pressure system. Thus the winds that influence Hong Kong are quite dry (Fig. A).

Furthermore, the high summer temperatures in Hong Kong (with an average around. 27 C) are likely to induce rainfall too. When the land, surfaces are overheated, strong vertical air currents set up. As the air ascends, ite temperature is reduced until condensation takes place and clounds are forged, The water droplets in the clouds will become bigger with further ascent, which means further cooling. In time the water droplets in clouds become too big and heavy to be saturated, rain begins to fall. This type of rain ie known as convectional rain- fall, Hong Kong, being ait- uated in the tropical lati- tudes, the convectional rain- fall is especially character- istic in summer. "(PIG, C)

Cumulonimbus clouds

of

around Deep Bay, the southwest

Lantao Island and the Tsing Yi Island. Such a geographic d distribution indicates an oro-

This is because, graphic effect. as mentioned above, most of the rain in long Kong is brought by onshore monaoons which blow mainly in an esterly direction from the sea. As the moisture- laden winds meet themountains, they will be forced to rise. They are then cooled, condensation thus occurs and clouds are formed. Being subjected to much the same process as those in the rising air currents as heated, water droplets fall down at last,

Thus the mountain regions, espec- ially the east-facing slopes in Hong Kong, have more rain because of this orographic effect. By the time the winds reach the lowlying western part, they are depleted of moisture. As they descout the leeward slopes, they are warmed by compression. Consequently, there is little rain and these areas are referred to

areas. (FIG. D) FORMATION OF ORO - GRAPHIC (KELIEF) RAIN

aB rain FIG. D

lives of condensation.

As air ascends.

28 jecomes coder

Ang Saturated

R+H, #ves

As air descends

it tømpressed Wstcomes

Vis survië P. -- Rim. fwis

MOUNTAIN

MASS

SHADOW

SEA

questions for next week:

Using the following: figures. describe the variations of wether elements on the day recordeu

16.18

"23 23

1925 25 24 23 23 24 19 33 34 33

Rejstive

! Humidity 95 95 97 48 15 ·63 44 66 95 AS

Local

"Arsing

time.

100

joz!!

· WAITO":

Chro

Ving amber

Temp

denger Jair.

LAND SURFACE HEATED BY THE SUN.

FIG. A THE SUMMER MONSOUN

OF ASIA

NTENSE

AESSURE

HONG KONG

HIGH

HORSE

LAY

Besides the monsoons, the seasonal distribution of rainfall in Hong Kong is also greatly affected by taphoons. The typhoons, which attack Hong Kong mostly from may sto September, are always accom- panied by turrenciai ((rige B)

FIG.

MAIN : TYPHOON. TRACKS IN THE WEST PACIFIC OCEAN

PHONG KHÁNG

Mut of the tropi [ess cyclones a fe

formed to the

of the

Philippines

The geographical distribution OF rainfall in Hong Kongt

FIG. II is the annual rainfall map of Hong Kong. The map shows that the areas with maximum rain-, fall (over 2,200 m.m.) cdncide with highland areas, e.g. Tai ko Shan region and Lantao Shan region. The areas with the lowest amount of rainfall (below 1,800 m.m.) lies on the west, .......... The northwest lowland

Rain fast (mmi

-7.

FIG. 1 and 11 shows the layouts o two arming areas in long foug Study them carefully and answer the. following:

A.

Suggest the crops that may be grown in aach farming area, giving your reasons. b. Describe and explain. tue

forms of settlement in

each

FIG. I

·DUCK POND

YONG TSENG

FIG. IIIK

B

TAI FO-TAU

LOP

300 M

AWW vi lages and houses

AKO

Narrow koad Tath

Main Road Woodland - Contour (H.)

River

Hailway

經

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