内容正文:
R — 111— — 112— R
9.
>?@A
:
æ$ï
£ÆIJ
1.(1)
ÝG
Ýë
+�
(2)
TÅ
2ݺk�lc
(3)
X
wGx
(4)
×�*¦0K#á
(5)
Ñ�Ò�s~[0ÒÓ
2.(1)
ݰ¡Þ
(2)
ú
、
ÿ
(3)
ÿ
、
u
(4)
*µ:4]
,
-X:406xí
,
xe0E=6Õ
,
!0ݰ
6¡
3.(1)
Ýë×*µ
(2)
*s
(3)
*
ïH
4.A
5.(1)
�
(2)
÷Ø*µ
üý¢
(3)
�üý¢Åz40TÅÍ�
(4)
z³"0
,
}IJ�G#&QÉ
,
)ã0^O2Z£f°
,
z2
Z�&°
,
ØåFz4SS0üý¢
,
ħXüý¢¤ÈDTÅ
�
6.(1)
ÜZ�éSÝ÷xÍ�
(2)
ÜZW³�V
(3)
�éSÝ÷
x�
(4)
W³*°
éSÝ÷x
(5)
-
(6)
Øå#ýÝë
¡Þzs
,
J*swo�r;
,
ÙÚ*µ�¹º0lc£H
7.(1)N (2)
�
ÝG
(3)
ïH
1.2 (4)
*µ
#(*¦
æ$f
£Æéê
1.́ :(1)
�Û*°7Ï2*~
:R
'2
=
U1
I0
= 6V
15×10-3A
=400Ω,
�?ÿ®
R
Ï2
=100Ω。#(*~ R0~·vìI:
R0=R
'2
-R
Ï2
=400Ω-100Ω=300Ω,
fg[[�½#�]
,
�Û*°70'*~
:
R
'
=
U1
Imax
= 6V
8×10-3A
=750Ω,
f$*~0~·
:R=R
'
-R
Ï2
=750Ω-300Ω=450Ω,
�?ÿ�®
,
\]g�I
70℃。
(2)
�!<:*°?®
:
wþ/¿�]
,R1、R2ÙZ,*fg[F�
Îf\]
,P
Îf
=U
2
R1
+U
2
R2
=2200W,̧ R2=2R1,
@Û
U2
R1
+U
2
2R1
=2200W,3U
2
2R1
=2200W,
Ô
3×(220V)2
2R1
=2200W,
´)
:R1=33Ω,R2=2R1=66Ω;Þß!<�®,*ÝX*[iTå
î:åî
c
vå]
,
*fg[F�#�\]
,
B�*°?®
,
\]
R2、R3{Z,Þß*~0{Zìî:ÕÖ�e�)#�ST:P
#�
=
U2
R2+R3
=110W,
Ô
(220V)2
66Ω+R3
=110W,́
)
:R3=374Ω。
(3)
g¿o0f/
:Q
¿
=cm(t-t0)=4.2×10
3J/(kg·℃)×
44kg×(50℃ -20℃)=5.544×106J,
Þßf�T�õ η=
Q
¿
W�)
,
Îf*°¾¿0+/
:
W
Îf
=
Q
¿
η
=5.544×10
6J
90%
=6.16×106J,
Îf]�
:t=
W
Îf
P
Îf
=6.16×10
6J
2200W
=2800s。
2.́ :(1)0.6
(2)
±g¼I
2m
]
,RF=60Ω,R0=R
'
-RF=
U
Ia
-RF=
12V
0.1A
-60Ω=60Ω,±g¼I1m],�,§=ß® RF′=90Ω,
*Ýþxe0*µ
:Ib=
U
R0+RF′
= 12V
60Ω+90Ω
=0.08A。
(3)
�MN*°®
,
Ñg:lÑÈá-ÙZ0
,
ÑgÈá g¼
1m
�½ÑgG
2m,
Ñg0'o½
:V
'
=0.4m2×(2m-1m)=0.4m3,
Ñg]�
:t1=
0.4m3
0.005m3/s-0.001m3/s
=100s,
g¼
2m
�qG
1m,
>§0]�
:t2=
0.4m3
0.001m3/s
=400s,
@ÛÑgÈáÇlÑÈá4]MN]
,
MN*°*µ�S
:
W=U2I2t1=220V×2A×100s=4.4×10
4J,
lÑÈá��MN]
,
MN*°*µ�S
:
W′=U2I1t2=220V×1A×400s=8.8×10
4J,
@Û:¥Ê&�
½pg�Ñg0C�]��
,
MN*°¾¿0*+
:
W
'
=W+W′=4.4×104J+8.8×104J=1.32×105J。
3.́ :(1)42
E
(2)
>¢±xe70*µ��«h�
0.2A
]
,
X*[0wþ/¿³
,
�ÕÖ�e®
,
�Û*°0'*~vìI
R
Ï2
=3V
0.2A
=15Ω,Þß
*~0{Zìî
,
Æ$*~
R
0Ï2·I
R
Æ
=R
Ï2
-R0=15Ω-
1Ω=14Ω,�,7=ß®,Æ$*~0ÆC¡H>§L3.0cdÛi。
(3)
2
4.́ :(1)
�*¦��%VST
:P′=U′I′=220V×100A=22000W,
�*¦��%ãST
:P