1、 2017 2018 70 90 30 . . 3 1 A B C D 2 A B C D 3 V A B C D 4 L1 L2 A S1 S3 S2 B S1 S2 S3 C S2 S3 S1 D S2 S1 S3 5 A B C D 6 5A A B C D 7 3 100 8 V1 V2 L1 L 2 R R R R S L L L L S S S A B C D A 2V 10V B 10V 2V C 2V 8V D 8V 2V 9 10 A B C D 24 2 11 12 2016 10 17 7 49 F 2 F 13 a b c a b c . 0 1 2 3 10 5 0
2、15 V 15 3 V2 S L2 V1 L1 14 a b 15 S 1 2 A 16 26 17 4 18 6 19 6 20 10 17 1 2 2 2 18 A B 1 2 A B 3 A B 19 a b c 3 2 1 1 Ib/A Ic/A Ia/A 0.18 0.18 0.36 S 2 3 20 4 m mm 2 A 0.25 1.0 B 0.50 1.0 C 0.25 2.0 D 0.25 1.0 1 M N 2 M N B C 3 M N A B A B 4 5 4 A B C D 10 21 4 22 6 . 21 A1 1.2 A A2 0.5 A. L1 I1 L2
3、I2 4 22. 50kg 10 50 0.8kg q=4.2 10 7 J/kg c=4.2 10 3 J/(kg ) (1) 50kg 10 50 (2)0.8kg (3) 6 2017-2018 30 3 0 1 2 3 4 5 6 7 8 9 10 C D B A C D B D C A 2 24 11 12 13 14 15 L2 0.28 16 ( 26 17 4 18 6 19 6 20 10 ) 17 2 2 18 1 2 2 B 2 3 B 2 19 1 2 2 2 3 2 20 1 2 2 A C 2 3 2 4 . 2 5 C 2 ( 10 ) 21 L1 L2 1 A1 I 1.2A 1 A2 L2 I2 0.5A 1 L1 I1 I I2 1.2A 0.5A 0.7A 1 22. Q =cm t-t0 =4.2 10 3 J/ kg 40kg 50 -10 =8.4x10 6 J 2 Q =mq=0.8kg 4.2 10 7 J/m 3 =3.36 10 7 J 2 25% 2
