{"common":{"save":0,"post_id":"8860","level":3,"total":10,"point":10,"point_extra":0},"segment":[{"id":"8345","mon_id":"1158790","chapter_id":"1159899","post_id":"8860","question":"<p>L&ograve; xo c&oacute; \u0111\u1ed9 c\u1ee9ng k, m\u1ed9t \u0111\u1ea7u treo v&agrave;o \u0111i\u1ec3m&nbsp;c\u1ed1 \u0111\u1ecbnh, \u0111\u1ea7u c&ograve;n l\u1ea1i \u0111\u01b0\u1ee3c g\u1eafn v&agrave;o v\u1eadt c&oacute;&nbsp;kh\u1ed1i l\u01b0\u1ee3ng m. Khi v\u1eadt c&acirc;n b\u1eb1ng th&igrave; h\u1ec7 th\u1ee9c&nbsp;n&agrave;o sau \u0111&acirc;y \u0111\u01b0\u1ee3c nghi\u1ec7m \u0111u\u0301ng?<\/p>","options":["<strong>A.<\/strong> <span class=\"math-tex\">$\\dfrac{k}{\\Delta l}=\\dfrac{m}{g}$<\/span>","<strong>B.<\/strong> <span class=\"math-tex\">$mg=k\\Delta l$<\/span>","<strong>C.<\/strong> <span class=\"math-tex\">$\\dfrac{g}{\\Delta l}=\\dfrac{m}{k}$<\/span>","<strong>D.<\/strong> <span class=\"math-tex\">$k=\\dfrac{\\Delta l}{mg}$<\/span>"],"correct":"2","level":"3","hint":"","answer":"<p>Ch\u1ecdn&nbsp;<span style=\"color:#16a085;\"><strong>B.<\/strong>&nbsp;<span class=\"math-tex\">$mg=k\\Delta l$<\/span>.<\/span><\/p><p>Khi l&ograve; xo c&acirc;n b\u1eb1ng, ta c&oacute;:&nbsp;<span class=\"math-tex\">$F_{\u0111h}=P$<\/span>&nbsp;hay&nbsp;<span class=\"math-tex\">$mg=k\\Delta l$<\/span>.<\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2025-04-14 08:26:25","option_type":"math","len":0},{"id":"8347","mon_id":"1158790","chapter_id":"1159899","post_id":"8860","question":"<p>M\u1ed9t l&ograve; xo c&oacute; chi\u1ec1u d&agrave;i t\u1ef1 nhi&ecirc;n b\u1eb1ng 22&nbsp;(cm). L&ograve; xo \u0111\u01b0\u1ee3c treo th\u1eb3ng \u0111\u1ee9ng, m\u1ed9t \u0111\u1ea7u&nbsp;gi\u1eef c\u1ed1 \u0111\u1ecbnh, c&ograve;n \u0111\u1ea7u kia g\u1eafn m\u1ed9t v\u1eadt n\u1eb7ng.&nbsp;Khi \u1ea5y l&ograve; xo d&agrave;i 27 (cm), cho bi\u1ebft \u0111\u1ed9 c\u1ee9ng l&ograve;&nbsp;xo l&agrave; 100 (N\/m). \u0110\u1ed9 l\u1edbn l\u1ef1c \u0111&agrave;n h\u1ed3i b\u1eb1ng<\/p>","options":["<strong>A.<\/strong> 500 N","<strong>B.<\/strong> 5 N","<strong>C.<\/strong> 20 N","<strong>D.<\/strong> 50 N"],"correct":"2","level":"3","hint":"","answer":"<p>Ch\u1ecdn&nbsp;<span style=\"color:#16a085;\"><strong>B.<\/strong> 5 N.<\/span><\/p><p>\u0110\u1ed9 bi\u1ebfn d\u1ea1ng c\u1ee7a l&ograve; xo:&nbsp;<span class=\"math-tex\">$\\Delta l=27-22=5(cm)=0,05(m)$<\/span>.<br \/>\u0110\u1ed9 l\u1edbn l\u1ef1c \u0111&agrave;n h\u1ed3i b\u1eb1ng:&nbsp;<span class=\"math-tex\">$F_{\u0111h}=k.|\\Delta l|=100.0,05=5(N)$<\/span>.<\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2025-04-14 08:29:18","option_type":"txt","len":0},{"id":"8349","mon_id":"1158790","chapter_id":"1159899","post_id":"8860","question":"<p>Ph\u1ea3i treo m\u1ed9t v\u1eadt c&oacute; kh\u1ed1i l\u01b0\u1ee3ng b\u1eb1ng bao&nbsp;nhi&ecirc;u v&agrave;o l&ograve; xo c&oacute; \u0111\u1ed9 c\u1ee9ng<br \/>k = 100 N\/m \u0111\u1ec3&nbsp;l&ograve; xo d&atilde;n ra \u0111\u01b0\u1ee3c 10 cm? L\u1ea5y g =&nbsp;10 m\/s&sup2;.<\/p>","options":["<strong>A.<\/strong> 1 kg","<strong>B.<\/strong> 10 kg","<strong>C.<\/strong> 100 kg","<strong>D.<\/strong> 1000 kg"],"correct":"1","level":"3","hint":"","answer":"<p>Ch\u1ecdn&nbsp;<span style=\"color:#16a085;\"><strong>A.<\/strong> 1 kg.<\/span><\/p><p>Khi l&ograve; xo c&acirc;n b\u1eb1ng, ta c&oacute;:&nbsp;<\/p><p><span class=\"math-tex\">$F_{\u0111h}=P$<\/span>&nbsp;hay&nbsp;<span class=\"math-tex\">$k\\Delta l=mg$<\/span>&nbsp;&rArr;&nbsp;<span class=\"math-tex\">$m=k\\Delta l:g=100.0,1:10=1(kg)$<\/span>.<\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2025-04-14 08:31:55","option_type":"txt","len":0}]}