HERBAR
日三廿月九年电戉夏
KIU YAT PA
1969
題預習
一九六九年
鮮試題
物理科
(-)
陸永熾
英文科(二)
劉士俊
PHYSICS (2)i:
JUSTER
1.4(8) Mass and weight
quantity of datter A?. a tudy.
"Inert is of a body which
pakest resist. accelerazio
Depends only on the material and size of
a body...
Constant.
Scalar quantity
Unit g
Measured by tomam balance
Weight
The downward pull which 18 experienced when holding a body in the hand."
Force which makes a body accelerate Lowards the centre of the Earth.
Depends also on the presence of the cart.
Varies from place to place. Vactor quantity.
Unit: dyne gmwt.
pdi. lb.ut. newton kg,wl.
Measured by spring balance.
Put a tick
against the word or group of
words which best completes the meaning of each Rentence
(6) What is the time?
shall be
does
Tolock
18 stolen has been atesling
Some hody
was stealing.
ay
has stolen
was stolen
期
日三十月一十年八六九一整公布七
seg the top of the clouds. C
(1) Daddy knew that Alison was looking at him. [
(3) They were flying scross the Atlantic Ocsán.
*I* Lay the short form of "I am
following short forma in full
(a) I've
you're
(0) I'll
(a she's
Taba't
(g) hasn't
Write the
Put each of the following words in the correct space cup, chopsticke. plate, knife, fork, spoon, bowl. (a) I put mý rice in a
(b) The fruit was put on a
(c) I drink tea out of a
Chinese people use
people use a
(e) He takes his soup with a
5. ANIMAL means REAST
Was Paning "shall be
Look at the ae sentences
good exerclas
will be would be
Please to chut
the window.
would shut have shut
up and tell me the truth,
now?
The giraffe is a trange anisai.
Bree; The giraffe te a strange beast.
olant.(
against the correct word.
hope you will forgive me.
thank
Put a tick
T hope you will forget( pardoni
(b) John bought a new pen.
purchased(
John borrowed
stole
a new
(c) Prepare for the holidays.
Density and specific gravity
Vensity of a substance is the mass per unit volume of that substance....
pahit must be noted that (1) density has no reference to weight, and (11) in expressing the value of density of a substance, the units of mass and volume must be stated clearly, e.g. gram per cubic centimetre and pounds per cubic foot.
The specific gravity of a substance is the ratio of the mass or weight of any volume of the substance to the mass or weight of any equal volume of soMD standard substance, s
In the case of solids and Liquids the standard is pure water at 4°C. In the case of gases the standard 15 usually hydrogen,
It must be noted that specific gravity is merely
a number it bears not units.
Standing Stand
Stood
Be standing Would stand
would leave shall leave
(f) May I left.
leave leaving
went
did go
(g) Henry go
market yesterday,
was gone gona
(h) whose pencil be
Dress
Get ready Work
For
nolidays
but English
(b) Archimedes' Principle
When ■ body is wholly or partially inversed in a fluid it experiences an upthrust equal to the weight of the fluid displaced. Application of the Principle – hydrometer
A hydrometer is an instrument used for measuring the specific gravity or density of a liquid. The specific gravity of liquid is measured by the amount of liquid displaced and which is read on the part of the stem floating above the liquid.
By the Archimedes' Principle:
upthrust on hydrometer
weight of liquid displaced
weight of the
Since the ting hydrometer
Since the weight of the hydrometer is constant, w; and the stem above water is the specific gravity is
sp.gr. oc
In general a hydrometer is not as accurate as a specific gravity bottle for determining the density or specific gravity of a liquid, owing to the downward pull on the hydrometer due to the surface tension of the liquid in which it is placed.
(e) To extend the range of reading of the
hydrometer as to measure the specific gravities of a variety of Liquid, weights are added to the hydrometer. The method of measurement is illustrated in part (d) of this problem.
Mass of hydrometer 50 gm.
When placed in water, the volume submerged, below the mark K, 19 Vicle, and, the cross-section of
the stem is a sq.c
• 50 ... (1) ..
When placed in brine and with an additional mass of 5. gm. the top, it sinks to K again,
Vx 3.6. of brine
5.G. of brine *
50
The S.G. of brine is 1,1
Thrust and Pressure
hrust is defined as a push force while pressure is the normal thrust acting on a area.
unit
Thrust bears unit of force- dyne, gaswt. poundal, lb-wt,; newton, kg,-wt.; etc.
The units of pressure are dyne/sq.cm., gm.wt./sq.cm,; pdl./sq,10., 1b.wt./sq.in, newton/sq.m., kg.wt./sq.m.
(b) The pressure in liquid is measured by;-)
hdg (dynes/sq.cm.
hd (gm.wt./@q.om
(1) tressure acting on the top face!
20 gm.wt./sq.cm.
Ans.
Pressure acting on the bottom
-70 gm.wti/80.cm.
2
"Ann
(11) Thrust acting on the top face
på gm. wt.
20 x 20 g, wt.
400 gm WCF
Arig.)
shall
are
goes
(i) Jene with her brother are going.
shall go should be going.
school.
Reing.
silent in
Should Would
Read the following barraza, carefully a
Alison opened her eyes and wondered where she She was flying to America, Through the window of the air-iiner she saw a sea of pink cotton-wool far below. It was the top of the clouds. Thousanda of feet below the clouds was the Atlantic Ocean,
Everyone else in the air-liner seemed to be. asleep. At her side, her brother John was sleeping. soundly, Daddy seened to be asleep, too, but when she looked at him he opened his eyes, winked at her and shut them again. You never knew with Daddy,"
Here are ten sentences ahout the passage. Five of them are true, Put a tick (v) against the five sentences that are trua.
(a) All the passengers in the air-liner were sleeping.
(b) The aeroplane was flying to England.(
(c) Alison could see the Atlantic Ocean far below.
(d) Daddy was sleeping soundly Ch
(e) John was sleeping by the side of her brother,
(f) Alison was very tired. ()
(g) They were going to America. A
(h) Through the window of the air-liner Alison could
Inrust acting on the bottom
- 70 x 20 1400 gm
Ans
(111) The thrust acting on the button exceeds that on the top of the object by
(1400 – 400) gm.wt.
That is, the upthrust of water on the object). is 1000 gm.wt., which is the weight of water displaced by the object.
(c) In the diagram AD represents the original water level, ED; is the column of oil 5 cm long, and C is the final water level in the other limb.
Since the tube, may be assumed of uniform bore, the length of water column must be constant, and therefore AC » BD..
By the Laws of hydrostatics, the pressures at D and Fare equal, so that the column of water CR exerts the same pressure as the column of oil ED 7
We use 4 kaffe for cutting.]
employ
Wear grind
Ta knife for cutting.
e) Try to do better next time.
Push Strive Stretch
{}
to do better next
(f) School begins at nine.
rises.
School closes
commencea
at nine.
(g) A kind girl has many frienda
kind girl has requent
thick
(b) The matter changed his mind.
formed:
The matter fixed
altered
bis min
(1) He saw three fisbaimen passing by.
heard
He beheld
ched
Answers LOTEST
three fishermen passing by
of, (b) with, (c) with, (d) in, (e) after. for, (g) on, (b) for, (1) of, (j) of. May, (b) Can, (c), must, (a) must, (e) Hay, ought, (g) ought, (h) must, (i) Can, (3)
ight.
have, (b) shall, (c) did not. (d) think t
Buckingham Palace, please.
noisily, (b) folded, (c) tickets, (d) Besson,
mine.
Bwin. (0) Bade, (0) Swimming, (4) 18 better, smells,
since
本機逢星期一
CF x 15 x 0.8.
CF-4 cm.
CA CF
2-cm
五挑出
Ans. The water will rise 2 cm., in the limb
of the U-tube.
Questions for this week;
1. (a) Describe an experiment to find the density of
cork using Archimedes' Principle. Give full details of the readings to be taken and explain how the result is calculated.
(b) Uraw a diagram to show four identical
spheres of specific gravity 0.2, 0.8; L.QU; and 2.00 as they would appear in a beaker of (1) water (11) alcohol (0,8); (iii) vladerine (1.3).
(c) What loan count just be ftea of the ground
by a spherical balloon of 2 metres in diameters. containing hydrogen at atmospheric pressure if the mass of the envelope and fittings is 100 gm.?
Density of nyurugen – U...uy gm./1ltra Density of air 1.29 gm./litre
Moscride one LSID, prung.
If the water is lifted in a tube 240 ft. high, what is the pressure due to this water on the side value? About how many atmospheres is this pressure? (Density of water, 02.5 lb,/c.ft.); ((b) What are the factors governing the pressure at any point in a liquid? Describe une simple- axperiment to show that the pressure below the surface of a liquid increases with depth. Explain the action of the hydraulic press.
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