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 cơ bản

{"common":{"save":0,"post_id":"6276","level":1,"total":10,"point":10,"point_extra":0},"segment":[{"id":"9723","post_id":"6276","mon_id":"1158739","chapter_id":"1158830","question":"Ta có th\u1ec3 nghe th\u1ea5y ti\u1ebfng vang khi<\/p>","options":["A. âm ph\u1ea3n x\u1ea1 \u0111\u1ebfn tai ta tr\u01b0\u1edbc âm phát ra.","B. âm tr\u1ef1c ti\u1ebfp \u0111\u1ebfn sau âm ph\u1ea3n x\u1ea1 th\u1eddi gian $\\frac{1}{15}$<\/span> giây.","C. âm phát ra và âm ph\u1ea3n x\u1ea1 \u0111\u1ebfn tay ta cùng m\u1ed9t lúc. \n ","D. âm ph\u1ea3n x\u1ea1 \u0111\u1ebfn sau âm tr\u1ef1c ti\u1ebfp th\u1eddi gian l\u1edbn h\u01a1n $\\frac{1}{15}$<\/span> giây."],"correct":"4","level":"1","hint":"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.<\/p>","answer":"<\/span>Ta có th\u1ec3 nghe th\u1ea5y ti\u1ebfng vang khi âm ph\u1ea3n x\u1ea1 \u0111\u1ebfn sau âm tr\u1ef1c ti\u1ebfp th\u1eddi gian l\u1edbn h\u01a1n $\\frac{1}{15}$<\/span> giây. \u0110áp án \u0111úng: D. âm ph\u1ea3n x\u1ea1 \u0111\u1ebfn sau âm tr\u1ef1c ti\u1ebfp th\u1eddi gian l\u1edbn h\u01a1n $\\frac{1}{15}$<\/span> giây.<\/strong><\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"147","test":"0","date":"2022-09-24 10:55:58","option_type":"math","len":0},{"id":"9724","post_id":"6276","mon_id":"1158739","chapter_id":"1158740","question":"Các v\u1eadt ph\u1ea3n x\u1ea1 âm t\u1ed1t th\u01b0\u1eddng có \u0111\u1eb7c \u0111i\u1ec3m nào?<\/p>","options":["A. M\u1ec1m, x\u1ed1p, g\u1ed3 gh\u1ec1.","B. M\u1ec1m, nh\u1eb5n.","C. C\u1ee9ng, nh\u1eb5n.","D. C\u1ee9ng, x\u1ed1p, g\u1ed3 gh\u1ec1."],"correct":"3","level":"1","hint":"Vâ\u0323t liê\u0323u c\u01b0\u0301ng co\u0301 bê\u0300 m\u0103\u0323t nh\u0103\u0303n thi\u0300 pha\u0309n xa\u0323 âm tô\u0301t.<\/p>","answer":"A, B, D la\u0300 ca\u0301c vâ\u0323t hâ\u0301p thu\u0323 âm tô\u0301t. \u0110áp án \u0111úng: C. C\u1ee9ng, nh\u1eb5n.<\/strong><\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"147","test":"0","date":"2022-09-24 10:56:57","option_type":"txt","len":2},{"id":"9725","post_id":"6276","mon_id":"1158739","chapter_id":"1158740","question":"\u0110i\u1ec1n t\u1eeb thích h\u1ee3p vào ch\u1ed7 tr\u1ed1ng: N\u01a1i ô nhi\u1ec5m ti\u1ebfng \u1ed3n là n\u01a1i có …..<\/p>","options":["A. ti\u1ebfng nói chuy\u1ec7n.","B. ti\u1ebfng máy móc ho\u1ea1t \u0111\u1ed9ng.","C. ti\u1ebfng \u1ed3n.","D. ti\u1ebfng hát hò."],"correct":"3","level":"1","hint":"\u01a0\u0309 nh\u01b0\u0303ng n\u01a1i th\u01b0\u01a1\u0300ng xuyên co\u0301 tiê\u0301ng ô\u0300n, ta no\u0301i môi tr\u01b0\u01a1\u0300ng sô\u0301ng ta\u0323i \u0111o\u0301 bi\u0323 ô nhiê\u0303m tiê\u0301ng ô\u0300n.<\/p>","answer":"N\u01a1i ô nhi\u1ec5m ti\u1ebfng \u1ed3n là n\u01a1i có ti\u1ebfng \u1ed3n. \u0110áp án \u0111úng: C. ti\u1ebfng \u1ed3n.<\/strong><\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"147","test":"0","date":"2022-09-24 10:58:51","option_type":"txt","len":2}]}