Phản xạ âm, chống ô nhiễm tiếng ồn

Home Lớp 7 Khoa học tự nhiên 7 - Sách kết nối tri thức Bài 14: Phản xạ âm, chống ô nhiễm tiếng ồnBài tập nâng cao

{"common":{"save":0,"post_id":"6278","level":3,"total":10,"point":10,"point_extra":0},"segment":[{"id":"9743","post_id":"6278","mon_id":"1158739","chapter_id":"1158740","question":"Phát bi\u1ec3u nào d\u01b0\u1edbi \u0111ây là sai?<\/p>","options":["A. M\u1eb7t n\u01b0\u1edbc c\u0169ng là m\u1eb7t ph\u1ea3n x\u1ea1 âm.","B. V\u1eadt h\u1ea5p th\u1ee5 âm t\u1ed1t: len, d\u1ea1, bông, m\u1ec1n, t\u01b0\u1eddng g\u1ea1ch s\u1ea7n sùi, cát.","C. V\u1eadt ph\u1ea3n x\u1ea1 âm t\u1ed1t là m\u1eb7t gi\u1ebfng, m\u1eb7t \u0111á ph\u1eb3ng, t\u01b0\u1eddng g\u1ea1ch ph\u1eb3ng, m\u1eb7t bàn ph\u1eb3ng.","D. M\u1eb7t \u0111\u1ea5t ph\u1ea3n x\u1ea1 âm t\u1ed1t."],"correct":"4","level":"3","hint":"+ Vâ\u0323t pha\u0309n xa\u0323 âm tô\u0301t la\u0300 vâ\u0323t c\u01b0\u0301ng va\u0300 nh\u0103\u0303n. + Vâ\u0323t hâ\u0301p thu\u0323 âm tô\u0301t la\u0300 vâ\u0323t mê\u0300m, xô\u0301p va\u0300 gô\u0300 ghê\u0300.<\/p>","answer":"D sai vi\u0300 m\u0103\u0323t \u0111â\u0301t gô\u0300 ghê\u0300. \u0110áp án \u0111úng: D. M\u1eb7t \u0111\u1ea5t ph\u1ea3n x\u1ea1 âm t\u1ed1t.<\/strong><\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"147","test":"0","date":"2022-09-24 11:23:30","option_type":"txt","len":3},{"id":"9744","post_id":"6278","mon_id":"1158739","chapter_id":"1158830","question":"Bi\u1ec7n pháp nào sau \u0111ây không <\/strong>ch\u1ed1ng \u0111\u01b0\u1ee3c ô nhi\u1ec5m ti\u1ebfng \u1ed3n? <\/p>","options":["A. Tr\u1ed3ng nhi\u1ec1u cây xanh d\u1ecdc hai bên \u0111\u01b0\u1eddng trong khu \u0111ô th\u1ecb. \n ","B. C\u1ea5m bóp còi to t\u1ea1i nh\u1eefng khu v\u1ef1c c\u1ea7n yên t\u0129nh nh\u01b0 b\u1ec7nh vi\u1ec7n, tr\u01b0\u1eddng h\u1ecdc. ","C. S\u1eed d\u1ee5ng các thi\u1ebft b\u1ecb b\u1ea3o h\u1ed9 nh\u01b0 nút tai, m\u0169 b\u1ea3o hi\u1ec3m, ch\u1ee5p tai... ","D. H\u1ea1n ch\u1ebf s\u1eed d\u1ee5ng \u0111èn qu\u1ea3ng cáo, \u0111èn chi\u1ebfu sáng trên \u0111\u01b0\u1eddng ph\u1ed1 gi\u1edd cao \u0111i\u1ec3m."],"correct":"4","level":"3","hint":"Các bi\u1ec7n pháp ch\u1ed1ng ô nhi\u1ec5m ti\u1ebfng \u1ed3n là: + Ph\u1ea3n x\u1ea1 âm trên \u0111\u01b0\u1eddng truy\u1ec1n: tr\u1ed3ng nhi\u1ec1u cây xanh d\u1ecdc hai bên \u0111\u01b0\u1eddng trong khu \u0111ô th\u1ecb \u0111\u1ec3 khi âm truy\u1ec1n \u0111\u1ebfn cây xanh s\u1ebd b\u1ecb ph\u1ea3n x\u1ea1. + Tác d\u1ee5ng tr\u1ef1c ti\u1ebfp vào ngu\u1ed3n âm: C\u1ea5m bóp còi to t\u1ea1i nh\u1eefng khu v\u1ef1c c\u1ea7n yên t\u0129nh nh\u01b0 b\u1ec7nh vi\u1ec7n, tr\u01b0\u1eddng h\u1ecdc. + Ng\u0103n c\u1ea3n âm truy\u1ec1n t\u1edbi: S\u1eed d\u1ee5ng các thi\u1ebft b\u1ecb b\u1ea3o h\u1ed9 nh\u01b0 nút tai, m\u0169 b\u1ea3o hi\u1ec3m, ch\u1ee5p tai... <\/p>","answer":"<\/span>A, B, C chô\u0301ng \u0111\u01b0\u01a1\u0323c ô nhiê\u0303m tiê\u0301ng ô\u0300n.<\/p>Bi\u1ec7n pháp không <\/strong>ch\u1ed1ng \u0111\u01b0\u1ee3c ô nhi\u1ec5m ti\u1ebfng \u1ed3n là: D. H\u1ea1n ch\u1ebf s\u1eed d\u1ee5ng \u0111èn qu\u1ea3ng cáo, \u0111èn chi\u1ebfu sáng trên \u0111\u01b0\u1eddng ph\u1ed1 gi\u1edd cao \u0111i\u1ec3m.<\/strong><\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"147","test":"0","date":"2022-09-24 11:24:38","option_type":"txt","len":3},{"id":"9745","post_id":"6278","mon_id":"1158739","chapter_id":"1158830","question":"Nh\u1eadn \u0111\u1ecbnh nào là sai <\/strong>trong các nh\u1eadn \u0111\u1ecbnh sau?<\/p>","options":["A. Dùng sóng âm \u0111\u1ec3 \u0111o \u0111\u1ed9 sâu c\u1ee7a \u0111áy bi\u1ec3n là s\u1eed d\u1ee5ng hi\u1ec7n t\u01b0\u1ee3ng ph\u1ea3n x\u1ea1 âm.","B. Ng\u01b0\u1eddi nghe th\u1ea5y ti\u1ebfng vang c\u1ee7a mình trong vách núi khi âm ph\u1ea3n x\u1ea1 nghe sau âm tr\u1ef1c ti\u1ebfp l\u1edbn h\u01a1n $\\frac{1}{15}$<\/span> s .","C. T\u01b0\u1eddng c\u1ee7a phòng hòa nh\u1ea1c th\u01b0\u1eddng \u0111\u01b0\u1ee3c treo rèm nhung \u0111\u1ec3 gi\u1ea3m s\u1ef1 ph\u1ea3n x\u1ea1 âm.","D. Ng\u01b0\u1eddi ta làm gi\u1ea3m \u0111\u1ed9 to c\u1ee7a ngu\u1ed3n âm b\u1eb1ng cách l\u1eafp c\u1eeda kính cách âm."],"correct":"4","level":"3","hint":"+ \u0110o \u0111ô\u0323 sâu cu\u0309a \u0111a\u0301y biê\u0309n la\u0300 \u01b0\u0301ng du\u0323ng cu\u0309a pha\u0309n xa\u0323 âm. + Khi âm pha\u0309n xa\u0323 truyê\u0300n \u0111ê\u0301n tai ta châ\u0323m h\u01a1n âm truyê\u0300n tr\u01b0\u0323c tiê\u0301p \u0111ê\u0301n tai ta mô\u0323t khoa\u0309ng th\u01a1\u0300i gian l\u01a1\u0301n h\u01a1n $\\frac{1}{15}$<\/span>  giây thi\u0300 âm pha\u0309n xa\u0323 \u0111\u01b0\u01a1\u0323c go\u0323i la\u0300 tiê\u0301ng vang. + Ca\u0301c vâ\u0323t mê\u0300m, xô\u0301p, gô\u0300 ghê\u0300 la\u0300 nh\u01b0\u0303ng vâ\u0323t hâ\u0301p thu\u0323 âm tô\u0301t.<\/p>","answer":"<\/span>D sai<\/span> vi\u0300 \u0111ây la\u0300 ca\u0301ch ng\u0103n ca\u0309n b\u01a1\u0301t s\u01b0\u0323 lan truyê\u0300n cu\u0309a tiê\u0301ng ô\u0300n \u0111ê\u0301n tai.<\/p>Nh\u1eadn \u0111\u1ecbnh nào sai là: <\/strong> D. Ng\u01b0\u1eddi ta làm gi\u1ea3m \u0111\u1ed9 to c\u1ee7a ngu\u1ed3n âm b\u1eb1ng cách l\u1eafp c\u1eeda kính cách âm.<\/strong><\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"147","test":"0","date":"2022-09-24 11:26:45","option_type":"math","len":0}]}