1970-05-22 — Page 23

華僑日報 All

#FOREI

LIBENT

育教僑華 頁三第張六第日八十月四年戌庚夏 WAH KIULYAT PO

報日僑華

2.2MAY 1970

CITY HALL

五期星日二廿月五年〇七九一曆公年九十五國民華中

英中會考附加數學(三)答案

in positive downward

3#$%$#5 #5 #65%3 #5 #%3 #%$#$%$ #2%S#$%$ #$%2

(讀)

堅道英文院撰答

Solution to H.K. Certificate of Education

Examination (English)

Additional Mathe, Paper III (Mechanics)

Section B

Si

中文中學售

試題預習專欄)

A

Component in the Ox direction

3500w A. + 29coad

*

52co

Component in the of 2.

13501aß

520227

35 • 2 - 52 •

2961 A

29.

--19 1b.ut. (negative Of direction)

Resultant moment anticlockwise direction

taken: to_ba positive)

-29 • 3eixα 52 • 2008/7 4:35

64 ft.lb.wt.

When the block is at equilibrium against elipping

P = Wainỡ + UWCOB

(1)

Take moment at C, the blook will overturn

P+2L > ¥• CE.

When

WCF LOOB A

HL(2tand + 1) c0s d ML(28ind

→→

COB X

(2)

From (1) the block will not slip but from (2) it will overturn.

11. a) Retardationg gino

0.4 Pt/

4000

b) Acceleration seen from the notion of the car

:20m

15 m.p.h.)2 - (30 m.p.h.)2

2 ( mile)

11.

2

Pulling force dus to the

4000 lb. (0.4 - 10)

800

Work done by this foron x y z 5280 KTIJDENT

物理科 (廿九)

鄧炳恩•

N. 直流電及歐姆定律問答計算題解

·肝()賞電镢s關閉時工=3安培,由歐姆定

A

R.與R,互联其「可 危阻

4x6

416-24in

(R2+R) × 3 = 12

R1 =42

R2 =4-24=1.6 (1)

R=6

(b) 當S 開啟時,設其電流為工,则

12

6716

=1.57 (安培),

Vor = Vig = B. C 点 之電位差

−1·57×6=942 ((**)

2解設電路中文

電流為工則

4+8

0.576+8+8:5+9

0.5(安培)

4

樊a点之電位差,則

E=8!

Ve - Va = (8+05)x 0-5-8 = -3-75(伏特)

即a点之電位较e点高3.75 伏特

設VC為E電池两端之霓压则

V1c = E, - Ir1 = 4 − 0.5×0.5 = 3.75 (UK°*)

及 工 = E/ CR+Y)得

3解: V=E -IY

Loss of Kis, of the dar

41,250 T1.id.ut.

ERE

RTY

==

YEL

• (1)

营1几與3丸之導線至联,其電阻為

R

In order to produce a total positive moment.

The direction of the resultant of X and Y is ahown in the Magram.

From the diagram tan ✪ 19

86 59*

Resultant of X and Y is √(192 + 12) - 19.0261b.wt

The I intercept of the line of resultant fora. is negativa and ite magnitude is given by d:

19.026 x doos86

4000(442

,904,000 ft.pal.

90,750 ft.lb.wt.

Gain of P.B. - ngh

4000 x 32 x x 5200 x 100 ft.

105,600 ft.lb.wt

f) Work done, against resistance

10g x = 5280 ft.pdź - 26,400 ft.lb.ut.

By conservation or energy work, qané by the pulling force ie (105,600,+ 26,400 - 90,750) ft.Jb.

41,250 ft.lb.wt. the same as in (0),

19.026 I OPB

63.92 rt.

ft

M.K.S, unite

Forve

Angular speed v

258

0.2

they intercept 18 -63.92 ft.

2L

When P la just large enough to cause motion the bisok will begin to move up. Friotional Toros F is given by

A woond

2W

When F

it cannot

wtart the motion of the block upward. It is greater than the downward component of the block Wein or W. So the

9 block is in equilibrium. From the condition of equilibrium frictional force is downward

2W

and its magnitude is given by 2~ - ~ - ~

The minimum value or to pull the block. upward is

downward

when of Pㄨㄢˇ

35 radian/

When the spring is inside the ring angular speed is increased to 63 radian/s

Force towards 0 is mou

1x 0.2 x 63

81 kg.wt.

Normal reaction on the spring

81-25 - 56 kg.ut.

Moment of frictional force about

56 x 0.25 x 0.2 n.kg.uk.

2.8 a.kg.t..

Power to overcome friction.

56 x 0.25 x 0.2 1.63 176.4

velocity of truck after K, 18 projectea

If V2 is in the opposite direction change

in (1)

ty after projection wELL DIOSES

= 0.5 (5)

=15 (V)

0. 電流之各種效应填-

並联之電灯150 枝 每枝之電阻 120 歐姆美 两端之電压為100伏特,由一發電机供给之 使10%之功率耗於電浆内组主上馬力等於)

馬力 746 瓦特则萨發電机之功率為

240燭光之電灯20枝每燭光用電卜4 瓦特 其電压为220伏特設每度電之電費為0.28 无則所用之全電流為每時電費多 3.放電阻線於1 立升之水中歷時1分鐘蒸温 度增高10°C,電阻缘两端之電压为100伏特 則

阻缘之電阻為.

4在硝酸银溶液中通以1安培之電流已知镢 電光当量为0.00 11 83.则欲析]克之纯银 需時。

5.三侗串联三月聶耳電池與銅電量計相連結, 時内祈出铜 31.7克已知钢原子量為

634,锌原子量:65,則同一時間内電池所祈 出钢为 及溶解之锌為

6.其電流於1分40秒内析出银0-112克於两倍 時間内析出钾0.081克已知银之化学当量為

正切電流計與 - 電池及一银電量計相串 联,斜之偏向为5於1小時内前出银0:105元 无鼓银之電化当量为0.001118則此正切電流 計之常數

8.正切電流計之缘圆共2匝半径15厘米與铜 電量計相串联:設偏向为60,且其磁场强度H

18 奥斯特,则於15分鐘内 出之銅步 正切電流計由三匝線圈组成其直径为30 厘 米通以085安培之電流則美 中心所生之磁 增强度為

毅当地之地磁水平强度為 0.17 奥則磁針之偏向角度為

電池一電流計與正切電流計串联,正功電 洗計以直径40厘米之十匝線圈组成,其偏向 為42,電流計指針所示为0.5157 安培則 当地之地磁水平强度為。

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