1、 ( ) 90 90 ( 13 2 26 ) 1 ( A ) A 26 cm B 5 m/s C 3 D 3 s 2 ( C ) A B C 340 m/s D 3 ( B ) A 0 B C D 4 ( C ) 5 ( D ) 6 ( D ) A B C D 7 ( B ) A B C D 8 ( B ) A B C D 9 ( D ) A B AB C D A A 10 S R P b ( B ) A B A1 C A2 D 11 ( C ) A B C D 12 ( D ) A FAFBFC B FAFB FC D FAFB FC 13 18 V 0 0.6 A 0 15 V V 3 (
2、 ) ( D ) A B 0.4 A 12 V C 10.8 W D 24 ( 8 1 22 ) 14 ETC ETC IC _ _( _ _ _ _ 15 ( ) _ _ _ _ _ _ ( ) 16 _ _( _ _( 17 30 s 500 N F 900 N 3 m 1.5 m F _50_W _90%_ 18 _ _ _ _ _ _ 5 kg _ 5 _J c 3J/ 19 _17.5_V _1.17_A( ) 20 v u _8_cm u 10 cm _ _ 12 cm 24 cm _ _ u 24 cm _ _ ,( 20 ) ,( 21 ) 21 10 N F A A 0.2
3、m/s _5_N _0.1_m/s ( 4 22 24 2 25 2 8 ) 22 0.5 kg ,( 22 ) ,( 23 ) ,( 24 ) 23 S S ( ) 24 F1 L2 25 ( 4 26 2 27 8 28 6 29 6 22 ) 26 (1) A B _ _ (2) 1 2 _ _ 27 U (1) _ _ _ _ _ _ (2) _ _ _ _ (3) _ _ _ _ _ _ _ _ 28 (1) _ _( (2) _ _ (3) _ _( _ ( )_ _ _( (4) _ _( 29 2.5 V 10 (1) ( A ) (2) _ _ _ _ (3) 2.8 V _
4、0.28_A _0.65_W U/V 1 2.5 2.8 I/A 0.18 0.26 (4) _ _ (5) _ _( ) ( 2 30 6 31 6 12 ) 30 AB O A B 10 cm 20 N C D OA OB C 2 cm AB (g 10 N/kg) (1) C (2) A (3) D G 20 N V (10 cm) 3 0.001 m 3 g 10 N/kg m G g 20 N 10 N/kg 2 kg m V 2 kg 0.001 m 3 3kg/m 3 C V (10 cm) 2 8 cm 0.000 8 m 3 3kg/m 3 F V g 10 3kg/m 3
5、0.000 8 m 3 10 N/kg 8 N A FA G F 20 N 8 N 12 N (3)A OA B FB OB OA OB FAOA FBOB OA FB OB FB 16 N D F G FB 20 N 16 N 4 N S (10 cm) 2 0.01 m 2 p F S 4 N 0.01 m 2 400 Pa 31 S S 220 W 2.5 L 1 min 40 s 220 V 84 3J/ (1) (2) (3) (1) I P U 220 W 220 V 1 A (2) W n N 84 r 3 600 r/kW h 4J P W t 8.4 10 4J 100 s 840 W (3) m 3kg/m 3 2. 3m 3 2.5 kg ) Q cm(t t0) 3J/ 5J t W P 8.4 10 5J 840 W 1 000 s
