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{"common":{"save":0,"post_id":"8114","level":3,"total":10,"point":10,"point_extra":0},"segment":[{"id":"8954","post_id":"8114","mon_id":"1159533","chapter_id":"1159595","question":"M\u1ed9t b\u1ec3 n\u01b0\u1edbc có \u0111\u1ed9 sâu th\u1ef1c t\u1ebf là 2m. Khi quan sát t\u1eeb trên không khí, b\u1ec1 m\u1eb7t n\u01b0\u1edbc trông nh\u01b0 ch\u1ec9 sâu 1,5m. Hãy tính chi\u1ebft su\u1ea5t c\u1ee7a n\u01b0\u1edbc.<\/p>","options":["A. 1,25","B. 1,33","C. 1,41","D. 1,50 "],"correct":"2","level":"3","hint":"","answer":"\u0110áp án: B<\/p>Gi\u1ea3i thích: Hi\u1ec7n t\u01b0\u1ee3ng khúc x\u1ea1 làm chi\u1ec1u sâu nhìn th\u1ea5y (chi\u1ec1u sâu \u1ea3nh) gi\u1ea3m so v\u1edbi chi\u1ec1u sâu th\u1ef1c t\u1ebf. Chi\u1ebft su\u1ea5t \u0111\u01b0\u1ee3c xác \u0111\u1ecbnh b\u1edfi công th\u1ee9c:<\/p>$n = {\\ chi\u1ec1u\\ s\u00e2u\\ th\u1ef1c\\ t\u1ebf \\over \\ chi\u1ec1u\\ s\u00e2u\\ \u1ea3nh}$<\/span> = $ {2 \\over 1,5} = 1,33$<\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"125","test":"0","date":"2024-12-01 09:43:44","option_type":"txt","len":0},{"id":"8955","post_id":"8114","mon_id":"1159533","chapter_id":"1159595","question":"M\u1ed9t th\u1ee3 l\u1eb7n nhìn th\u1ea5y m\u1ed9t v\u1eadt \u1edf \u0111\u1ed9 sâu d\u01b0\u1eddng nh\u01b0 là 2 m khi quan sát t\u1eeb trên không khí xu\u1ed1ng n\u01b0\u1edbc. Bi\u1ebft chi\u1ebft su\u1ea5t c\u1ee7a n\u01b0\u1edbc là n = 1,. Tính kho\u1ea3ng cách th\u1ef1c t\u1ebf t\u1eeb m\u1eb7t n\u01b0\u1edbc \u0111\u1ebfn v\u1eadt \u0111ó.<\/p>","options":["A. 2,5 m","B. 2,6 m","C. 3,0 m","D. 1,5 m"],"correct":"2","level":"3","hint":"","answer":"\u0110áp án: B<\/p>Gi\u1ea3i thích:<\/p>Ta có công th\u1ee9c: $n = {d_{ th\u1ef1c} \\over d_{\u1ea3nh}}$<\/span> <\/p>=> $d_{th\u1ef1c} = {d_{\u1ea3nh}.n}$<\/span> = 2.1,33 = 2,66 m ≈ 2,6 m<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"125","test":"0","date":"2024-12-01 10:12:32","option_type":"txt","len":0},{"id":"8956","post_id":"8114","mon_id":"1159533","chapter_id":"1159595","question":"M\u1ed9t kính thiên v\u0103n \u0111\u1eb7t trên Trái \u0110\u1ea5t quan sát các vì sao vào ban \u0111êm. Do hi\u1ec7n t\u01b0\u1ee3ng khúc x\u1ea1 ánh sáng trong khí quy\u1ec3n, ánh sáng t\u1eeb các ngôi sao b\u1ecb l\u1ec7ch kh\u1ecfi qu\u1ef9 \u0111\u1ea1o ban \u0111\u1ea7u. N\u1ebfu chi\u1ebft su\u1ea5t trung bình c\u1ee7a khí quy\u1ec3n là 1,0003, tính \u0111\u1ed9 l\u1ec7ch t\u1ed1i \u0111a c\u1ee7a tia sáng khi \u0111i qua khí quy\u1ec3n v\u1edbi góc t\u1edbi $89^\\circ$<\/span>.<\/p>","options":["A. 0,05°","B. 0,1°","C. 0,15°","D. 0,2°"],"correct":"1","level":"3","hint":"","answer":"\u0110áp án: A<\/p>Gi\u1ea3i thích: <\/p>\u0110\u1ed9 l\u1ec7ch c\u1ee7a ánh sáng \u0111\u01b0\u1ee3c tính d\u1ef1a trên s\u1ef1 chênh l\u1ec7ch gi\u1eefa góc t\u1edbi và góc khúc x\u1ea1. Áp d\u1ee5ng \u0111\u1ecbnh lu\u1eadt khúc x\u1ea1:<\/p>$\\sin r = {\\sin i\\over n}$<\/span> = ${\\sin 89\u00b0\\over 1,0003}$<\/span> ≈ $ {0,99985 \\over 1,0003}$<\/span> ≈ 0,99955 <\/p>=> r ≈ 88,95°<\/p>\u0110\u1ed9 l\u1ec7ch: $\u0394i=i\u2212r=89^o\\n \u221288,95^\\n =0,05^o\\n$<\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"125","test":"0","date":"2024-12-01 10:24:31","option_type":"txt","len":1}]}