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刋盏育教頁一第張叫第日四初月一十年丑癸圈夏

WAH KIU YAT PO

三期星

日八十月一十年三七九一曆公年二十六國民華中

方朝阳花

攝記本

影者報

黄歇子行本 大

多年

曲服

TIL

目節彩精項各節港香

(GRUIT

運輸箱頭什貸及米

1974中學會考試題預習專欄

U be the kupthrust of water,

Mg be the weight of the Body

M be the mass of the body and

堅道書院上海

4(slope

W

物理科

陸永爉:

graph): tane 2/2.5

10.07.

PHYSICS (4)

9.8

ms-2

displace-0.2.

0.4

(a)

Solution

ment (om)

time (sec)

averagy

velocity (cm/sec)..

Plotting a graph of ve

13

(sec)

(1) The trolley roves with a uniform

acceleration.:

(11) The slope of the graph measures

the acceleration. It is

AB .10

BC:

The acceleration is 10 cm-s* (iii) By Newton's Second Law of

Motion, ma

The mass, ma

20 1980 ..: 1.0. (takınız g as 980 cm-s2

.1960

The force that sinks the body, F. W-U Since F Ma, the acceleration in water = &= F/M.

The upthrust equals

to the weight of water displaced: -U Ng/0.75

W-U

Mg - 0775

u=10ms W=1ng.

(negative for retardation) When it sinks to a maximum depth; its velocity is zero, and the body starts floating up to, the surface again.

If H demotes the maximum depth,

-2a = v - u

2(-5)H

H

0

15

uat:

tü/a

(b) The period of oscillation of a

simple peridulum (T) depends on the pendulum length and the gravity (g)

The pendulum length is constant. The only factor affecting T is g The relative

oscillation:

of the simple

pendulum to:

the trolley

is due to.".

the component 9

Therefore,

g cose

Ecose

That is, ita period of oscillet- tion is longer than on 2 level plane!

(o) The mass possesses an initial

velocity, u, when released at a height of 217 m; 4 m/s

The time taken for the flight The displacement (a vector) rele tive to the starting point is S= 217 m

The acceleration = -·-·

u4m/

tat

5t

217 0 (5t + 3·1) t -7)=0

(t-7)=0

(b) A bell is dropped from rest or

to a horizontal ground of 10 m below. Assume that the ball re- bounds with of the velocity: with which it hits the ground, (1) find the time that elapses

between the first and the second impact,

1) Assuming that the time dur-

ing which the impact between the ball and the ground take 0.3.8, calculate the average force between the goound and the ball during the first impact if the mass of the ball is 1 gm.

State Newton's Laws of Motion (b) Are they all independent?..

Give reasons.

(c) Three blocks A,B,C of masses

1 kg, 2 kg, and m kg respect- ively, have a light inexter- sible string connecting B- and C. A and B are placed on a smooth inclined plane, of 309 with C. hanging over a smooth and weightless pul- ley at the top of the inclin ed plane.

(1) Find the value of m such.

that the system will be at reat.

WE CARE (11) Now suppose C is tapped

slightly so that the system acquires a a velocity of u What will happen then? (iii)Find the value, of m such that

O will move downwards with an acceleration of 1 m/s/s (iv)Find the tensions in the strings in case (iii)

7

takes 7 seconds reach the ground.

夏季

HCE

in kg

They are looking forward

seeing their uncle soon.

(A. at B. between C. among

D. of B. to :).

6. Aunt Margaret divided the

cakes

four aqual parts. (P. among Q. into R. between

S. for T. of )

There is no difference

these two books.

(P. between Q. among R. from

S. to D. at }

8. The waves beat

the rocks.

(P. over Q. against R. with

S. to T. from)

9. The swimmer dived.

sea last night. (P. ing. to R.

T. from)

10. It is a pity that our new

car has broken

nto

9. ( ).

suddenly. (P. up Q. out R. down S. into

T. off)

10. ()

SECTION. B

Fill in the blanks with the

following preposi

from, of, for in, on, with, at, to, up, off, by

Judging

Ovel

I guess that

this stone may weight up.

your help..

service

dust.

(b) Braphical method

(m/L

The time taken for this downward. flight is t sec.

10 x 3/g 35

The upward flight consumes the same. time duration, therefore,

the total time required = 3 + 3.

8.06

-250 200.7. 4:03

AB

- G-seconds

TIME

Vel. of tram passing the 1st pole

= u m/s.

Vel. of tram passing the 2nd pole

15 m/s

Distance between the two poles

Area ABCD

(BC + AD) CD

(15+)5

50

In

(15+ u)5 = 50

15 + v = 20

The velocity of the tram on passing

the first pole is 5 m/s.

The acceleration is measured by the slope of the graph

6. Solut

Pendulum length

Period of swing -

100T

4-50 347:9:14:de

2-100 317.4.10.07

150 283.9 -200 245.9 6.05

When the graph.

As produced, it

will cut the x-

axis at 0.

QA 14. 1.

CD 100

CO - 10.07;

A.

BO και AD

2 mg

By the Equation of Motion

Sut +at

.50

5u+(25)a

20

= 2u + Sa

گرا

- น + at

15

u 5a

(1), (2)

u = 5 ma

Subat. into (2)

2 ms

(2)

QAB and

AB

DA

74.7

OCD are similar triangles

CD. 00

-100 0:07

1410

be the velocity of the aeroplane relative to the earth:

be the velocity of thi wind relative to earth

be the velocit of the plane to air

2VV cos(1804

-2V

橋準

1974 中學入學試

試題預習專欄

英文辣習

智慧出式柱主

SECTIONA

(multiple choice)

100 mph

40mph

-45°)

Choose the beat answer.

LETTER in brackets.

Write the

Example:

We are pointing

bird's nest.

the

(A. from B. out

at

D. in E. of).

(c)

=10000-1600+200x40 co3450

116008000/ 2 2 17257.7

V = 131.4 mph

The angle for direction of this. velocity is measured by sine law:

sin (180° - 450).

1:31.

sin

sin

40

40 sin45° 131.4 12926'S of W

Questions for the next week

1. The teacher often points

John's mistakes.

(A. off B. out Ga in D. of

E. from)

We shouli take pity. the

blind.

Don

(A. by B. of

E. to)

C. in

10.07 4.05

14. 1 - 1410

2349.9

→ 350 cm

The original length of the pendulum is 350 cm.

7. (a) A and B are two stations

700 m apart. A train starts from rest from A with constant accel- eration a; until it acquires a speed of: 20 m/s. It then travels with this speed for 5 min, and then is brought to rest by a constant retardation, b. Find (1) the values of a and b (ii) the total time of the

journey.

3. Those pupils are fond. playing football.

(A. at B. to C. of

by)

4. I an interested

funny stories. (A. in B. to.

E. from).

(ii) Since

T21

27

2. ()

D. from

3. (1

reading

C. with D. by

ܢܹܐ

2. I am thankful to you 3. We are pleased to have

to you.

4. They will leave here for Japan

24th December, 1973.

The desk was covered.

6. I bought that car:

price.

7. Joseph will be invited.

Mary,

'a very high

8. My grandfather has given

already.

dinner by

smoking

All

auty now?

9. Good students must read

their books.

10 Is the policeman

III. Fill in each blank with a suitable

Preposition.

Once upon a time thera was a very thirsty cat called Nancy. One day she found jug which is half full

milk. She tried very hard (2. Zap (3.

the milk but failed (4. do so. She couldn't reach the milk (5.) her tongue because the jug's neck was too narrow. All at once a

She good idea came (6.) her mind. dipped her paw (7.) the jug and brought it (8.) covered (9. milk. Then she licked the milk (10. her paw. She kept on doing this several times till the jug was empty.

ANSVERS

SECTION A: I. 1.C 2.D 3.0 4.A 5.3

6.0 7.P 8.9 9.5 10.R

SECTION B: II 1.from 2.for 3.of

4.on 5.with 6.at 7.to 8. up 9. through 10.off III: 1.of 2.to 3.up 4.to

5.with.into 7.into 8.out 9.with 10. off.

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