1、 ( ) 90 90 ( 13 2 26 ) 1 ( B ) A 5 V B C D 2 100 ( A ) A B C D 3 ( C ) A B C D 4 ( D ) A B C D 5 ( C ) 6 L ( B ) A L B C D 7 ( B ) A B C D 8 ( D ) A B C D 9 S P ( C ) A a N B b N C a S D b S 10 ( B ) A B C D 11 a b ( C ) A Fa Fb B pa pb C a b D 12 S P ( D ) A B C D 13 ( A ) A B C D ( 8 1 24 ) 14 (1)
2、 _ _ (2) _ _ _ _ (3) _ _ 15 _ _ _ _ 16 _ _ _ _ _ _ _ _( 17 _ _ _ _ 18 2 10 4m _ 8 _Pa 1.5 mm _ _ ( 3kg/m 3 g 10 N/kg) 19 3 000 _ 7 _N _ _( _ _ _ _ (g 10 N/kg) 20 U I _20_ _ _( 2 V _0.3_A 0.2 A _0.8_W ,( 20 ) ,( 21 ) 21 F _ _F p _p ( ( 4 22 24 2 25 3 9 ) 22 ,( 22 ) ,( 23 ) 23 N 24 l2 A F1 l1 25 ( ) (
3、 3 26 5 27 6 28 5 16 ) 26 u/cm v/cm 1 30 15 2 20 20 3 15 30 4 5 / (1) 1 _ _ _ _ (2) ( D ) A B C D (3) 3 _ _( (4) _ _ 27 2 (g) (min) 300 20 30 12 300 20 30 6 (1) _ _ _ _ (2) _ _ _ _ (3) _ _ (4) _B_ A B C D 28 (1) _ _ (2) _ _ (3) _S_ P _ _( (4) _ _ ( 2 29 6 30 9 15 ) 29 0.1 m 2 5 3 m 2 (g 10 N/kg) (1)
4、 (2) (3) (1) F G gV V 0.6 V F g0.6 V 3kg/m 3 10 N/kg 10 3m 3 0.6 6 N V V 0.6 3kg/m 3 (3) F F G 3kg/m 3 10 N/kg 10 3m 3 6 N 4 N p F S 4 N 2.0 10 3m 2 3Pa 30 R0 a b U I (1) R (2)R0 (3) R0 (1) a b R0 a 8.0 V 0.4 A b 0 1.2 A R U I 8.0 V 0.4 A (2) Um P a Um U IR0 8.0 0.4R0 P b Um IR0 1.2R0 R0 Um 12 V (3) I Um R0 R 2 12 V 10 10 0.6 A P I 2 R0 P (0.6A) 2 10 3.6 W
