{"common":{"save":0,"post_id":"8422","level":3,"total":10,"point":10,"point_extra":0},"segment":[{"id":"7160","post_id":"8422","mon_id":"1159539","chapter_id":"1159710","question":"<p>M\u1ed9t h\u1ecdc sinh \u0111o th\u1ec3 tích c\u1ee7a m\u1ed9t viên bi b\u1eb1ng cách th\u1ea3 viên bi vào bình chia \u0111\u1ed9 ch\u1ee9a 50 ml n\u01b0\u1edbc. Sau khi th\u1ea3 viên bi, m\u1ef1c n\u01b0\u1edbc dâng lên 65 ml. H\u1ecfi th\u1ec3 tích viên bi là bao nhiêu?<\/p>","options":["A. <span class=\"math-tex\">$15\\ cm^3$<\/span>","B. <span class=\"math-tex\">$50\\ cm^3$<\/span>","C. <span class=\"math-tex\">$65\\ cm^3$<\/span>","D. <span class=\"math-tex\">$115\\ cm^3$<\/span>"],"correct":"1","level":"3","hint":"","answer":"<p>\u0110áp án: A. <span class=\"math-tex\">$15\\ cm^3$<\/span><\/p><p>Gi\u1ea3i thích:<\/p><p>Th\u1ec3 tích viên bi chính là l\u01b0\u1ee3ng n\u01b0\u1edbc dâng lên: <span class=\"math-tex\">$V_{bi}=V_{sau}-V_{tr\u01b0\u1edbc}=65-50=15\\ cm^3$<\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"125","test":"0","date":"2025-02-09 10:20:00","option_type":"math","len":0},{"id":"7161","post_id":"8422","mon_id":"1159539","chapter_id":"1159710","question":"<p>M\u1ed9t kh\u1ed1i kim lo\u1ea1i có kh\u1ed1i l\u01b0\u1ee3ng riêng <span class=\"math-tex\">$D_1=8000\\ kg\/m^3$<\/span>. Ng\u01b0\u1eddi ta n\u1ea5u ch\u1ea3y nó và \u0111úc thành m\u1ed9t v\u1eadt khác có th\u1ec3 tích g\u1ea5p \u0111ôi ban \u0111\u1ea7u. Khi \u0111ó, kh\u1ed1i l\u01b0\u1ee3ng riêng c\u1ee7a v\u1eadt m\u1edbi là bao nhiêu?<\/p>","options":["A. <span class=\"math-tex\">$4000\\ kg\/m^3$<\/span>","B. <span class=\"math-tex\">$8000\\ kg\/m^3$<\/span>","C. <span class=\"math-tex\">$16000\\ kg\/m^3$<\/span>","D. Không xác \u0111\u1ecbnh \u0111\u01b0\u1ee3c."],"correct":"1","level":"3","hint":"","answer":"<p>\u0110áp án: A. <span class=\"math-tex\">$4000\\ kg\/m^3$<\/span><\/p><p>Gi\u1ea3i thích:<\/p><p>- Khi n\u1ea5u ch\u1ea3y, kh\u1ed1i l\u01b0\u1ee3ng v\u1eadt không \u0111\u1ed5i nh\u01b0ng th\u1ec3 tích t\u0103ng g\u1ea5p \u0111ôi.<\/p><p>- Kh\u1ed1i l\u01b0\u1ee3ng riêng \u0111\u01b0\u1ee3c tính: <span class=\"math-tex\">$D’ = {m\\over 2V}= {D.V\\over 2V}= {D\\over 2}= {8000\\over 2}=4000\\ kg\/m^3$<\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"125","test":"0","date":"2025-02-09 10:26:50","option_type":"math","len":0},{"id":"7162","post_id":"8422","mon_id":"1159539","chapter_id":"1159710","question":"<p>M\u1ed9t hình l\u1eadp ph\u01b0\u01a1ng có c\u1ea1nh 10 cm, kh\u1ed1i l\u01b0\u1ee3ng 2 kg. H\u1ecfi kh\u1ed1i l\u01b0\u1ee3ng riêng c\u1ee7a v\u1eadt này là bao nhiêu?<\/p>","options":["A. <span class=\"math-tex\">$2000\\ kg\/m^3$<\/span>","B. <span class=\"math-tex\">$5000\\ kg\/m^3$<\/span>","C. <span class=\"math-tex\">$1000\\ kg\/m^3$<\/span>","D. <span class=\"math-tex\">$200\\ kg\/m^3$<\/span>"],"correct":"1","level":"3","hint":"","answer":"<p>\u0110áp án: A. <span class=\"math-tex\">$2000\\ kg\/m^3$<\/span><\/p><p>Gi\u1ea3i thích: <\/p><p>- Tính th\u1ec3 tích kh\u1ed1i l\u1eadp ph\u01b0\u01a1ng: <span class=\"math-tex\">$V=(10\\ cm)^3= 1000\\ cm^3=0,001\\ m^3$<\/span><\/p><p>- Tính kh\u1ed1i l\u01b0\u1ee3ng riêng: <span class=\"math-tex\">$D = {m\\over V}= {2\\over 0,001}= 2000\\ kg\/m^3$<\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"125","test":"0","date":"2025-02-09 10:39:56","option_type":"math","len":0}]}
