... ti thi im t = 2s k t a bt u quay l A kgm2/s B kgm2/s C kgm2/s D kgm2/s HT - P N M 0 12 1B,2D,3B,4A,5C,6D,7D,8C,9D,10D,11B,12B,13B,14A,15C,16A,17D,18B,19B ,20 D ,21 A ,22 A ,23 C, 24 C ,25 A ,26 C ,27 B ,28 A ,29 D,30B,31D,32C,33B,34C,35B,36B,37B,38B,39D,40A, ... 3,1MeV U2 U2 20 + 80 = 100 = P= P 100 Gii cõu 9:Chn B 2 ( Z L ZC ) = 20 .80 = 40 P = R1 U2 R 12 + ( Z L Z C ) = U2 U2 Tng t: P2 82 122 Gii cõu 10 Chn B NPb 20 6 t mPb NA N 20 6 N0 ( e ) 20 6 20 6 ... tiu Cõu 29 Mt vt dao ng iu hũa x = 10 cos10 t ( cm ) Vn tc ca vt cú ln bng 50 ( cm s ) ln th 20 12 k t t = ti thi im Cõu 22 A 24 13 12 s B 120 7/ 12 s C 120 5 12 s D 24 15 12 s t in ỏp xoay chiu cú...