育教僑華頁三第張六第 B%+A=TERRE WAH KIU YAT PO
報日僑茶
三期星日五月二年九六九一愍公年八十五國民華中
(接第六張第二頁)
1969
物理科
(十四)
陸永燁
PHYSICS:(14)
25.50lution
If a given mass of gas at constant pressure za slowly cooled, its volums decreases uniformly with the temperature as shown by the straight lino AB. As the gas is cooled below 0°C. its
volume shrinks further and, theoretically, unere is a definite temperature at which the volume of the gas would become zero. This temperature 18. known as the absolute zero. When temperature are measured from the absolute zero they are said to be absolute temperatures, and are expressed in. "degrees Kelwin" (°K),
The absolute temperaturs TK corresponding to a temperature in Centigrade t°C is given by
1273 t
(b) Suppose the absolute temperature x°C below 0°C. Then, assuming the change in volume takes place at constant pressure, the volume is proportional to the absolute temperature. Hence
constant
1.035
The absolute zero so calculated is
270.790
20-cm. capillary tube 15 heated to get. rid of all traces of moisture and sealed in a flame at one end. A pellet of mercury about 2 cm. Long is introduced at the open and by heating and cooling. The tube is then tied to a clamped ruler together with a thermometer. The combination is put into a beaker of water which is heated by a bunsen burner. A constant stirring is made. The volume of the trapped air. and its temperature are taken. A graph of volume ágainst temperature is slotted showing that the volume of air increasea uniformly with temperatura
With open end upwards, Pressure of air trappsa (8 ~ 5) cm. of he Volume of air trapped
P1VI (H5) 22.4
with open end downwards, Fressure of air trapped
Yolume of air trapped -
212 ~ (H - 5) 25.6
22.4
(H5).
cm of g 25.6 cm. Long
Whère H ia the barometric Applying boyle's law
(115)22.5 CH-
32H 240
H=75
Ans. The atmospheric pressure 13.
merc
(0)
The pressure or air enclosed by the marcury pellet remains constant when. the temperature is raised, being equal to atmospheric pressure plus
cm. of mercury.
Therefore, applying Charles Jaw, and, suppose the pellet rises h ca
30..5
30.5 h
30.5
373
278
英文科
(十四) 劉士俊
Another "tax is paid on goods such as
A jewellery, new clothes, tobacco, vine,
when they are brought into a country. Such
tax is paid as part of the price of these goods
if they are later sold in shops. We call it
indirect tax, because it is paid indirectly through the shopkeeper.
Feople usually complain about having to pay taxes, but they forget that the money is spent on things that they and their families need. We need policemen to catch thieves. to see that
men obey the laws, to direct traffic, etc., and they must be paid what they carn; children need education and there must be schools and teacherni we want our streets to be kept clean, and the wages of men who do thie kind of work have to de paid.. About all, the country must always be ready to defend itself against attacking enemies, and
** we cannot have an army without paying for
Here are ten sentences about the story. Some of them are true and some are not. Put a tick against the ones that are true.
(a) The government decas money to pay for many
things();
b) The money the government needs can be supplied
by the people of the country..
(c) People should not pay money to the government,
(d) The government has a lot of money paid by
the people of other country.
(e) Tax paid according to a person's income 10
called a direct tax.
1)
A doctor should not pay income tax, [)
(1) A tax paid on goods is called direct tax. (1) People should not complain about having to pay
taxes. (a)
(1) The wages of government school teachers are
paid by the government..
If the word in capitais rhymes with one of the following words, write a letter against the number in the space. If you cannot find any word that rhymes with the word in capitale, don't write anything in the space.
Ereapleen
BLOOD
WATCH
(a) blew. (b) qua, (c) nad; (d) gön Fa) wash, (b) care. (4) march(d) teach
SIZE (a) these, bliss, (clbest,(d)fest PIGS (a)bees, (b)bags, (c)picks, (d) seeks LATER (a)fatter (thater, (c)letter, (d)bat (4) TOUR (a) boot, (b)boat)tore.(a) poor (5) PRICE (a) five. (b)kates. (c)kiša,(c) is.
Put a tick against the word which best completes the meaning of the passage
A poet once said "God made the
and but
country.
man made the town.
This
since.
20°C
Any change in temperature will affect both the pressure and volume of the introduced air in the tube. So, the gas squation is used:
V1
Assuming che mercury column at 40° to be Hcm, and the cross-sectional area of the tube.
Sq.cm.then:
273-201 293
1273
40 = 313
-76 51017
40 - 36 cm.
R}1cm.
Substituting into the gas equation
36 x 45a (76-H)(85 - Ha
293
313
-16 1H¥**5460*-*1730
#2}=-151H>=4730x=-0
161
16920
Unly the second solution is possible and therefore, the mercury stands at a height of 38.7 cm. at 40oC.
(a) To verify tharles! Lawifor gases
278
30.5
278.
1014
Ans. The pellet will rise iU.4 cm.
Questions for next week:
(a) Derine specific heat,
Name two different units or specific neat. (b) Describe how you would determine the specific
heat of a solid by a method of mixture.
(c) What volumes of iron, lead, and aluminium care: the same thermal capacity as a litre of water? The specific heat of iron, lead, and aluminium are respectively 0.12, 0.031, and 0.22; and their specific gravities, 7.5, 11.4 and 2.7. (d) Two exactly similar copper calorimeters, each
of mass 50 gm. contain 100 c.c. of water and turpentine respectively at a temperature of 90°. They are allowed to cool under identical conditions and is found that the times of cooling from 70° to 60°C are 5 min. 20 sec. water and 2 min. 7 sec. for turpentine, what is the specific heat of turpentine? Density of turpenting-0.87 gm./c.c. Specific heat of copper 0.10
28, (a) What is meant by the latent neat, or vapori
of a substance?
Name two different units of latent heat.
b) Describe how you would determine the latent
heat of vaporization of steam.
(o) Water in a vacuum flask is boiled steadily by passing an electric current through a coil of wire Immersed in the water. When the potential difference across the coil is 5.25 volts and the current through it is 2.58 amp.y 6.85 gm. of water evaporate in 20 min. When the potential difference and the current are maintained at 3.20 volts and 1.57 amp. respectively, 2.38 gm. of water evaporate in 20 min., all the other conditions being the same. Calculate the latent heat of vaporization of water in joules per gi
(d) (i) In melting to water at 8°C., g. or ice
at 0°C. give up 435 calories. Calculate the latent heat of fusion of ice. (ii) What mass of iron at 1790, droppea into.
liquid oxygen at its boiling-point (-183°C.) will cause 2 g. of oxygen to evaporate? (latent heat of oxygen 51 cal./gm.: ep.bt.sor iron(-0.09 cal./gm./°C.)
the country
MOTS most
beautifu
many
than a town and pleasante:
tox at
live in,
and
too
Many people think
also
this
, and go to the country
For the summer holiday
always even
nëver
BO
though they
cannot live there all the yea
around round too whole
Some
have a cottage in a village. Or
though and
go there
whenever they
could #111 can
ring the time, especially
· must
at weekends.
Answers to Test 13.
(a) were, (b) to do, (6) will be, (d) come, (e) had done, (1) fishing, (g) had done, (h) get, (1) came, (3) has lived.
(a) 1.3, 2.4, 3.0, (b) 1.3, 2.B, 3.a, 4.0, (c) 1.9, 2.-0, 3.A, (a) 1,0, 2.E, 3.D, 4.A, S.P. 6.B "Was it a man or a woman?" asked the shop-keeper. "A man, she answered.
"He was a friend of the woman at your table, said, the man,
"You must go back to your nouse very quickly, I will telephone to the police and ask a policeman to mees you there.".
let the traveller stay in his house. (b) he had lost his purse somewhere outside.
by the farmer'e son.
in the bushed..
e)by the farmer's son.
whom
tan, ailing zand