1968-01-24 — Page 23

育教健器 ̇直三第六第

日五廿月二十年未丁歷察

WAH KIU YAT PO

報

1963

育教僑華

題顯習髮

英文科 (十三)

何玉柱

D48英文中學會考試題預習專欄

物理科 (十三)

陸永熾

Answers to Exercise ITT:

Physics 137)

期星

日四廿月一年八六九一股公年七十五國民華中

The kind old man was apparently moved, "He said;)

"Don't cry. You may move in right now.

"Really?"

"Of course! I alwaysTM dean what I say?".

"Oh, thank you, thank you!" Then I turned to

beckon to my kids. "Coma,Iny_dear come thank Mr.

You can imagine the bewilderment and astonishment

on Mr. Law's face when out behind six tombatones came! ay children marching towards him!/:

23.

TEMP

Ice (solid) expands slightly when warmed from -10°C to 0°C; at 0°C it forms water and contracts. (Heat energy obtained by the ice is used to change the states instead to

raising the temperature). When water is warmed.. it contracts from 0°C to 4°C, which is exceptional, but from 4°C onwards it expands behaving now like most liquids,

(b)

besker

sta

conical flask and cotton-wool plug ara weighed (m), water 18 out in the flask and re-weighed (my), The weight of water is found (my - m). After taking the initial temperature (to), water is boiled in the

flask, fitted with cotton-wopi to retain any spray and covered with an upturned beaker to surround the flask with steam and so reduced heat Loses. The time taken for water to boʻ】 la opserved. Heating is continued for the same length of time and then the flask is put quickly into cold water to condense the steam still in the flask. When cooled, the arrange= ment la wiped dry and weighed (mg). From the loss in weight (1 mg), the water ooiled eway, the latant heat of steam sa calculated: Temperature (°c)

weightings (gram)

Flask plug

Flask plug water

(Final

..100

Water

-8189

After boiling.

- [my Laur]

Flask plug • water

Water boiled away

Sp.ht, of glasa

Heat supplied to flask and water

m) (100-

Assuming the same quantity"or'neat wors supplied during boiling period.

Latent heat of vaporisation of water lis

Laal/gm.

Heat supplied during boiling(period)

(my

́m}}"{100 -7tg)'

(3-6)}

(c) The latent'heat'offsteam is 540 cal/gmi

10 gm. of steam is passed into

In one

ice-cold water.

HONG

That is, 5400 cal. is given to the water (1) Amount of heat required to heat 320 gm.rof water, through 50 deg. Cils 320 x 50 onl

Time taken "I

320 x50 **]min.]*[2.96 min.]

5400

(11) Amount of heat requiredīto neat 320 gm. I of mater through 100 degree C. 16,32000

Time requiredjel

.92 min.

Bath processes take in hoạt,” Evaporation. takes place only from the exposed surface of liquid kharass boiling takes place in the whole body of the liquid. Evaporation does not occur at

1. 1) Shall we meet at the school "gara?

2)If it is posible, they will go abroan,).

3) I promise him that I will do my best.

4) After Jume, we shall have a long vacation.

5) Mary's parents have, arranged for her that she

shall first study music and then domestic science. [6) He proposed that they should go fishing on the

next Sunday,

7) The commander-in-chief has given the order that].

the soldiers shall never retreat whatever they may face.

8) The 'boy is sic

will a girl do in his place?

a) We know you need them, but as they are not avai

lable, will we do instead?:

10) If there is no fruit. vegetable will also do.)

1) He said they had to raish their work then.. 2) She told us that he had had the habit of

collecting stamps but then he had taken to: movie-going.

He said he ought to have helped her but he

refused to do 60

(4) He asked her if she nad been able to lift up

two hundred pounds bare-handed two years before.

1. Comprene is on

Read the following passage as many times as needed and then answer the questions set oa

we nad enough trouble in finding a place to ve Jeg the chief trouble was: no family wished

room or two with such a biz family as oure .. with so many children..

share

Everytime went 1-kept on praying all the time. But when the question, "How many children have you?" came, and my stammered answer, "Six, but they are all, well-behaved." was hardly given, I was refused, either apologetically or abruptly, I was given a definite "No". I could understand--with five boys aged from 4 to 13. and a child in her troublesome twoll, how could I complain?.

But that late afternode-to-bere practically" outcaste of the town. With a inaspezete prayer, I took my children to a suburb old cottage near a graveyard where I left my children and cautiously advised them to keep unseen. Then I wint along as usual, The land lord, Mr. Law, was kind. When he learnt I was a widow and my present condition, he sighed. Then came the dreaded question, "and have you children?

I could foretell__the_result of my answer "but I)

solo not 116. Tearfully, almost sobbingly. I said, "Yes Six." Then, pointing with trembling hand tow aveyard in the darken dusk, I added. "They ar

any articular temperature where as boiling does. Boiling depends on external pressure whereas evaporation is independent of atmosph- eric pressure.

(b) When air is cooled to a temperature that it can no longer hold all the water vapour present, it becomes saturated and condensed. The temperature of air when it becomes saturated with water vapour is known as the dew point.

Air

Dew Point

to aspira beri

Glass

Thimble

Ether

A simple Dew-point Hygrometer consists of two highly polished thimbles attached to the lower ends of two glass tubee. Both are fitted with thermometers. One is empty and serves merely for comparison purposes. The ether containg other, through which air may be bubbled) by means of an espirator.

As air bubbles in the ether, rate of evaporation increases. Cooling takes place. alety vapour will soon appear on the surface the thimble, and the temperature la noted.

1) Why couldn't the writer find a place for the

family to live in?

2) Had the writer any daughter? How many and how old?. 3) Who was the writer, the children's fatherfor

mother?

4) What happened to the other parent of the children's? 5) What made Mr. Law give his consent to rent his,

house?

6) Find words in the passage which mean”

a, nice and polite

b. people not wanted by anybody).

c. beginning of evening

d. call

e. place at the edge D1 a town)

2. Translate the following into Chinese!

The first thing that man learnt, as soon as' they began to study nature carefully, was that some events take place in regular order and that' some causes always give rise to the same effects. The sun always rises on one side and sets on the other; the seasons are more or less regular: water always flows down hill: plants grow up from seed and yield seed, from which like plants) grow up again; animals are borg, grow. reach maturity, and die, age after age in the same way. The more carefully nature has been studied, the more widely has order been found to prevail.) At present, no one is so foolish as to believe that anything happens by chance or that there say that thing are any real accidente. If we happens by chance, every body admits that all wer really gean is that we do not know its cause or the reason why that particular thing happens.>

Translate the following into Engen

張先生和夸先生是多年老友,人家媳是见他们俩

・大池被約制隔村去吃飯、途中経 森林,森林裡听说常有野獸出沒,他们就相

1713 13 200

̇到森林裡,他的一面误笑一面面图張望。 突然,李先生看到迎面表了一隻大然,他没有通知張. 克制自己就連忙往樹,爬。菜張先生發現時已巷 不爬樹只好躺在地上阅孟前装死。叶幸大陆

果他,也就走開了...

EL I IL TUT L 1978 ~ TOBZI

4e32 2. Zroopy - f PICOZMAZI 人做朋友吗

李先生・聴違う・禁酒面名

Note: to hold one's breath?

The tygrometer is then allowed to warm up and the temperature of disappearance of the daw i8; recorded. The dew point is taken as the maan of these two temperature.

If the room temperature is lowered, the dow point is not affected. It remains the same. However, if water is sprayed in the room the amount of water vapour increases air easily reaches ita saturation, Dew point is raised.

Questions for next week)

Massaplain, with diagram, how you could deviate

25. (a)

a beam of light through 180°, using (1) one plane mirror

(11) two plans mirror

b) What must be the angle between two plans mirrors

in order that a ray incident on one of them my,

after two reflections, be

(1) parallel to itself

(11) parallel to the first mirror

(111) travelling back along ito om path.

(o) Two lamps of 16 c.p. and 25 c.p. are 180 cm.

apart, a screen is placed 60 cm. from the

mrror

(1) compare the illumination on the two 81065

of the screen

(ii) where must it be placed to be equally

Illuminated on both sides?

26. (a) A ray of light travelling in air strikes the

surface of a block of glass. It is observed that the angle of reflection la 27°5' when the angle of incident is 46°30*.

Calculate the refractive index of glass,

(b) Another ray makes an incident angle of 60o, with the same glass block. Calculate the angle of refraction.

Le) Find the angle or refraction when a ray of

light travelling on the blook makes an angi of 200 at the interface of water (refractive index - 1.3).

What is the critical angle for this glase? (d) What is the critical angle for glass-water?