大学物理课后习题答案(北邮第三??- 百度文库 ر

11-3ͼ

?11-3 11-3ͼʾ+qٶvO˶+qOľΪxO㴦

?뾶ΪaԲƽ棬ԲƽvֱͨԲλƵ ⣺11-3ͼʾqƽxʱͨԲƽĵλͨ

?D?(1?۴˽ϰ8-9(3)

q2xx?aqa2v22)

d?D ID??dt2(x2?a)322

11-4ͼ

-1511-4 11-4ͼʾƽаڸĽ糡ǿE=720sin10?tVm涨ͼ

(1)еλƵܶȣ

(2)ھr=10mһPt=0t=

-2

1?10?5sʱųǿȵĴС2(ǴĴų) ⣺(1) jD? jD??0?D,D??0E ?t?E???0(720sin105?t)?720?105??0cos105?t A?m?2 ?t?t???? (2) ?H?dl??I0??jD?dS

l(S)ȡ뼫ƽΪԲģ뾶rԲl?2?r

H2?r??r2jD

rH?jD

2t?0ʱHP?t?r?720?105??0?3.6?105??0A?m?1 21?10?5sʱHP?0 211-5 뾶ΪR=0.10mԲ幹ƽаУԵٳ磬

dE13-1-1

ʹ糡ı仯Ϊ=1.010 VmsλƵ

dtԲr(rR)ĴŸӦǿBrԼr=RĴŸӦǿBR

?D?E??0: (1) jD? ?t?tID?jDS?jD?R2?2.8A

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????(2) ?H?dl??I0??jD?dS

lSȡƽڼ壬ΪԲĵԲl?2?r

H2?r?jD?r2??0 H?dE2?r dtrdE?0 2dt??rdEBr??0H?00

2dtr?RʱBR??0?0RdE2dt?5.6?10?6 T

-2

-3

-1

*11-6 һߣ뾶Ϊ10mλȵĵΪ310mе25.1 AԼھർ߱ܽһ¸ (1)HĴС

(2)Eƽڵ߷ϵķ (3)ֱڵ߱S

: (1) Hdl?????I

ȡ뵼ͬĴֱڵߵԲl?2?r

H2?r?I IH??4?102A?m?1

2?r(2)ŷķ΢ʽ j??E

I/S?IR?7.53?10?2 V?m?1

?1/RS?????(3)S?E?H,Eص,Hֱ ??2Sֱ߲뵼ߣСS?EH?30.1W?m

*11-7 һԲε壬뾶ΪaΪ?,еI0

?E(1)ڵھΪrijĵĴСͷ

?(2)õHĴСͷ

?(3)õӡ͢ʸSĴСͷ

(4)(3)Ľ볤Ϊl뾶ΪrĵĵȽϣ

I:(1)ܶj0?0

Sŷķ΢ʽj0??E

E??jI0һ

??a2(2)ȡԵΪԲģֱڵߵƽԲl?2?r

???? ?H?dl??j0dSɵ E???j0??lSj0r2H2?r?I02

aI0r 22?a???(3) S?E?H

? Sֱڵ߲뵼ߣСΪ

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?I02rS?EH? 242?a(4)Ϊl뾶Ϊr(r?a)ڵλʱΪ

I0r22I0?lr2l W1?I01R?(2)?2?4a?r?aλʱ볤Ϊl뾶Ϊrڵ

2I0?lr2 W2?S2?rl?4?aW1?W2˵εĵǵų뵼ߵ

22*11-8 һܳ߹ܣÿλnѣ뾶Ϊaһӵĵi (1)߹ھΪrһĸӦ糡 (2)ӡʸĴСͷ : (1)߹ B??0ni

????B??dS ?E?dl???lS?tȡԹΪģֱƽԲl?2?rBϵ

?BE2?r???r2

?t???0nrdir?Bdi???0ʱEBϵ E??Բ򣬵

dt2?t2dt??di?0ʱEBϵ dt11-8ͼСΪ

??????(2) S?E?HEH֪Sָᣬͼʾ.

S?EH?Eni??0n2rdi2idt

-1

*11-9 һƽŲIJΪ3.0cm糡ǿȵΪ30VmʸõŲƵΪ

2

?ųǿȵΪ?һֱڴΪ0.5mȫ棬õŲƽѹǿǶ? : Ƶ??c??1.0?1010Hz

1E0H0ɵ 2B0??0H0??0?0E0?1.0?10?7T

ڵŲжֱ䵽һΪAȫձʱ?tʱյĵŶΪgAc?tǸñܵĵŲƽѹǿΪ

?r?0E??r?0HS?SEHP?gC??00?C2C?0E02?4.0?10?9 Pa

?02CɼŲķѹǿ(ѹ)Ǻ΢ģ

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ϰʮ

12-1 ijɫӿˮУƵʡ١Ƿ仯?仯?

?ս: ?䣬ΪԴƵʣ?n?Сu??n?С

n12-2 ˫ʵУµʱĻϵĸƽα仯?˵ɣ (1)ʹ֮ľС

(2)˫಻䣬ʹ˫ĻľС (3)װõĽṹ䣬ȫˮУ

(4)ԴƽS1S2߷΢Сƶ (5)һ͸ıĸƬסһ죮 : ?x?D?֪(1)Ʊ裻(2)Ʊܣ(3)Ʊܣ(4)㼶Ļd2?෴ƶ(5)㼶ƶ

12-3 ʲôǹ? ڲͬľýУɫͨĹʱ伸·Ƿͬ?ʱǷͬ?ڹ̲λĹϵʽ???в,Ϊʲô?

:??nrͬýȣ伸·̶ͬʱͬΪ?t???,ⲨIJҪ

? CΪ?Ѿڽе·Ϊߵ·̡

12-4 12-4ͼʾABƽ岣ɿ⣬ƽα仯?

(1) AشֱBķƽƣۼͼ(a)ݣ (2) Aʱתۼͼ(b)ݣ

12-4ͼ : (1)???2lek?k?2֪߷ƶƼ಻䣻

(2)߷ƶƱܣ 12-5 ⹤ƽȣΪ?ĵɫⴹֱʱ,۲쵽ĸ12-5ͼʾÿһƵֵĶǡڵֱֵ߲У˵ȱ͹ǰ?ȱݵij̶ȣ

: ȱǰģʸȺ(ȱݸ)߷⣬ÿһֵĶǡڵֱ߲У˵൱ƶһӦĿ϶ȲΪ?e??2Ҳǹȱݵij̶ȣ

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