{"id":117,"date":"2021-09-26T09:32:21","date_gmt":"2021-09-26T07:32:21","guid":{"rendered":"http:\/\/yb-isn.fr\/2021\/spc\/?p=117"},"modified":"2022-09-25T10:21:25","modified_gmt":"2022-09-25T08:21:25","slug":"phenomenes-ondulatoires","status":"publish","type":"post","link":"https:\/\/yb-isn.fr\/2021\/spc\/?p=117","title":{"rendered":"Ph\u00e9nom\u00e8nes ondulatoires"},"content":{"rendered":"<p><!--more--><\/p>\n\n\n<h2 class=\"has-black-color has-cyan-bluish-gray-background-color has-text-color has-background wp-block-heading\" id=\"01\">1)Diffraction<\/h2>\n\n\n\n<p class=\"has-small-font-size\">Le ph\u00e9nom\u00e8ne de diffraction de la lumi\u00e8re par une fente: exp\u00e9rience<\/p>\n\n\n\n<figure class=\"wp-block-image is-resized\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/yb-isn.fr\/ts42019\/wp-content\/uploads\/2019\/09\/diffraction-taches-1024x410.png\" alt=\"\" class=\"wp-image-124\" width=\"512\" height=\"205\"\/><\/figure>\n\n\n\n<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/yb-isn.fr\/num\/wp-content\/uploads\/2019\/09\/retenir-e1569656528481.jpg\" alt=\"\" width=\"55\" height=\"55\">Le ph\u00e9nom\u00e8ne de diffraction s&rsquo;observe quand la lumi\u00e8re (ou plus g\u00e9n\u00e9ralement toute onde) rencontre sur son chemin un obstacle ou une fente d&rsquo;une dimension de l&rsquo;ordre de grandeur de sa longueur d&rsquo;onde. Alors les lois de l&rsquo;Optique g\u00e9om\u00e9trique ne s&rsquo;appliquent plus, mais l&rsquo;image (figure de diffraction) sera toujours centr\u00e9e sur l&rsquo;image g\u00e9om\u00e9trique<\/p>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/yb-isn.fr\/spe-physique-2020\/wp-content\/uploads\/2020\/09\/probouvertdifr-300x219-1.png\" alt=\"\" class=\"wp-image-208\" width=\"300\" height=\"219\"\/><\/figure>\n\n\n\n<p class=\"has-vivid-cyan-blue-color has-text-color\">  probl\u00e8me ouvert : <a href=\"https:\/\/colab.research.google.com\/drive\/1zIb-8wDrQX4xCpQ45pU7F7bEn56eN7kk?usp=sharing\">Corrig\u00e9<\/a><\/p>\n\n\n\n<div class=\"wp-block-media-text alignwide\" style=\"grid-template-columns:37% auto\"><figure class=\"wp-block-media-text__media\"><img decoding=\"async\" src=\"http:\/\/yb-isn.fr\/ts42019\/wp-content\/uploads\/2019\/09\/houle.png\" alt=\"\" class=\"wp-image-19 size-full\"\/><\/figure><div class=\"wp-block-media-text__content\">\n<p class=\"has-small-font-size\">Le ph\u00e9nom\u00e8ne de diffraction est aussi observ\u00e9 dans les ports avec la houle qui est une onde m\u00e9canique.<\/p>\n\n\n\n<p>voir cuve \u00e0 onde<\/p>\n<\/div><\/div>\n\n\n<div class=\"container theme1\" style=\"width:100%; height:auto\"><ul class=\"responsive-accordion responsive-accordion-default bm-larger\"><li><div class=\"responsive-accordion-head\" style=\"background-color:\"><span style=\"color:;font-size:15px\">Animation : diffraction<\/span><i class=\"fa fa-chevron-down responsive-accordion-plus fa-fw\"><\/i><i class=\"fa fa-chevron-up responsive-accordion-minus fa-fw\"><\/i><\/div><div class=\"responsive-accordion-panel\"style=\"background-color:;padding:12px;color:;font-size:14px\"><p><iframe loading=\"lazy\" src=\"https:\/\/www.edumedia-sciences.com\/fr\/media\/frame\/160\/?auth=0ecb23fe918f2225ea66dfa8d94deda1\/23383\" width=\"550\" height=\"440\" frameborder=\"0\"><\/iframe><\/p>\n<\/div><\/li><\/ul><\/div>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter is-resized\"><img decoding=\"async\" src=\"http:\/\/yb-isn.fr\/ts42019\/wp-content\/uploads\/2019\/09\/diffraction-e1569826655739.png\" alt=\"\" class=\"wp-image-10\" width=\"409\"\/><\/figure><\/div>\n\n\n<p>La diffraction de la lumi\u00e8re par une ouverture ou un obstacle laisse penser que la lumi\u00e8re se manifeste comme une onde.En effet On observe aussi le ph\u00e9nom\u00e8ne de diffraction avec les ondes m\u00e9caniques comme la houle.<\/p>\n\n\n\n<p>La lumi\u00e8re est une onde \u00e9lectromagn\u00e9tique de c\u00e9l\u00e9rit\u00e9 c<\/p>\n\n\n\n<p>c=3&#215;10<sup>8<\/sup>m\/s<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter\"><img decoding=\"async\" src=\"http:\/\/yb-isn.fr\/ts42019\/wp-content\/uploads\/2019\/09\/difrretenir-1024x219.png\" alt=\"\" class=\"wp-image-27\"\/><\/figure><\/div>\n\n\n<p>L\u2019importance du ph\u00e9nom\u00e8ne de diffraction en g\u00e9n\u00e9ral est li\u00e9e au rapport :<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter\"><img decoding=\"async\" src=\"http:\/\/yb-isn.fr\/ts42019\/wp-content\/uploads\/2019\/09\/teta.png\" alt=\"\" class=\"wp-image-119\"\/><\/figure><\/div>\n\n\n<ul class=\"wp-block-list\"><li>\u03b8  : ouverture angulaire du faisceau en&nbsp; radian (rad)<\/li><li> \u03bb  : longueur d\u2019onde dans le vide de la lumi\u00e8re utilis\u00e9e (m) <\/li><li> a  : largeur de la fente (m)  <\/li><\/ul>\n\n\n\n<figure class=\"wp-block-embed is-type-wp-embed is-provider-specialite-physique-chimie wp-block-embed-specialite-physique-chimie\"><div class=\"wp-block-embed__wrapper\">\n<blockquote class=\"wp-embedded-content\" data-secret=\"N9vyiUVA5n\"><a href=\"https:\/\/yb-isn.fr\/2021\/spc\/?p=242\">TP n\u00b04 diffraction + corrig\u00e9<\/a><\/blockquote><iframe loading=\"lazy\" class=\"wp-embedded-content\" sandbox=\"allow-scripts\" security=\"restricted\" style=\"position: absolute; clip: rect(1px, 1px, 1px, 1px);\" title=\"\u00ab\u00a0TP n\u00b04 diffraction + corrig\u00e9\u00a0\u00bb &#8212; Sp\u00e9cialit\u00e9 Physique-Chimie\" src=\"https:\/\/yb-isn.fr\/2021\/spc\/?p=242&#038;embed=true#?secret=y4iKoakkD1#?secret=N9vyiUVA5n\" data-secret=\"N9vyiUVA5n\" width=\"600\" height=\"338\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\"><\/iframe>\n<\/div><\/figure>\n\n\n\n<p>Exercice 43, 46 et 47 page 479<\/p>\n\n\n<div class=\"container theme1\" style=\"width:100%; height:auto\"><ul class=\"responsive-accordion responsive-accordion-default bm-larger\"><li><div class=\"responsive-accordion-head\" style=\"background-color:\"><span style=\"color:;font-size:15px\">corrig\u00e9s<\/span><i class=\"fa fa-chevron-down responsive-accordion-plus fa-fw\"><\/i><i class=\"fa fa-chevron-up responsive-accordion-minus fa-fw\"><\/i><\/div><div class=\"responsive-accordion-panel\"style=\"background-color:;padding:12px;color:;font-size:14px\"><p><a href=\"https:\/\/yb-isn.fr\/2021\/spc\/wp-content\/uploads\/2021\/10\/exosondescor.pdf\" class=\"pdfemb-viewer\" style=\"\" data-width=\"max\" data-height=\"max\"  data-toolbar=\"bottom\" data-toolbar-fixed=\"off\">exosondescor<br \/><\/a><\/p>\n<\/div><\/li><\/ul><\/div>\n\n\n\n<h2 class=\"has-black-color has-cyan-bluish-gray-background-color has-text-color has-background wp-block-heading\" id=\"02\">2)Interf\u00e9rences<\/h2>\n\n\n\n<p class=\"has-black-color has-text-color\">Comment expliquer <strong>Expliquez les ph\u00e9nom\u00e8nes observ\u00e9s<\/strong>?<\/p>\n\n\n\n<figure class=\"wp-block-gallery has-nested-images columns-default is-cropped wp-block-gallery-1 is-layout-flex wp-block-gallery-is-layout-flex\">\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" data-id=\"129\" src=\"http:\/\/yb-isn.fr\/ts42019\/wp-content\/uploads\/2019\/10\/baiestjeandeluz.png\" alt=\"\" class=\"wp-image-129\"\/><\/figure>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" data-id=\"130\" src=\"http:\/\/yb-isn.fr\/ts42019\/wp-content\/uploads\/2019\/10\/bulle-1.png\" alt=\"\" class=\"wp-image-130\"\/><\/figure>\n<\/figure>\n\n\n<div class=\"container theme1\" style=\"width:100%; height:auto\"><ul class=\"responsive-accordion responsive-accordion-default bm-larger\"><li><div class=\"responsive-accordion-head\" style=\"background-color:\"><span style=\"color:;font-size:15px\">Animation : interf\u00e9rences<\/span><i class=\"fa fa-chevron-down responsive-accordion-plus fa-fw\"><\/i><i class=\"fa fa-chevron-up responsive-accordion-minus fa-fw\"><\/i><\/div><div class=\"responsive-accordion-panel\"style=\"background-color:;padding:12px;color:;font-size:14px\"><p><iframe loading=\"lazy\" src=\"https:\/\/www.edumedia-sciences.com\/fr\/media\/frame\/749\/?auth=f99310746eba612e76d41b416489e666\/23383\" width=\"400\" height=\"300\" frameborder=\"0\"><\/iframe><\/p>\n<\/div><\/li><\/ul><\/div>\n\n\n\n<p class=\"has-black-color has-cyan-bluish-gray-background-color has-text-color has-background has-medium-font-size\">2a) Le ph\u00e9nom\u00e8ne physique<\/p>\n\n\n\n<p>Les interf\u00e9rences s&rsquo;obtiennent \u00e0 partir de deux sources dites <strong>coh\u00e9rentes<\/strong>.<\/p>\n\n\n\n<p>Les franges d&rsquo;interf\u00e9rences s&rsquo;obtiennent lorsque les ondes issues de sources coh\u00e9rentes se superposent.<\/p>\n\n\n\n<p>Des sources coh\u00e9rentes ont la m\u00eame fr\u00e9quence et vibrent en phase \u00e0 chaque instant.<\/p>\n\n\n\n<p>Exp\u00e9rimentalement on obtient des ondes coh\u00e9rentes en divisant une m\u00eame onde.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" src=\"http:\/\/yb-isn.fr\/spe-physique-2020\/wp-content\/uploads\/2020\/10\/Capture-d\u2019\u00e9cran-2020-10-01-171944.png\" alt=\"\" class=\"wp-image-256\"\/><\/figure>\n\n\n<p>Superposition de deux ondes sinuso\u00efdales (somme de deux sinus)<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-209 size-full\" src=\"http:\/\/yb-isn.fr\/2021\/spc\/wp-content\/uploads\/2021\/09\/sinusplus.png\" alt=\"\" width=\"620\" height=\"305\" srcset=\"https:\/\/yb-isn.fr\/2021\/spc\/wp-content\/uploads\/2021\/09\/sinusplus.png 620w, https:\/\/yb-isn.fr\/2021\/spc\/wp-content\/uploads\/2021\/09\/sinusplus-300x148.png 300w\" sizes=\"(max-width: 620px) 100vw, 620px\" \/><\/p>\n<hr>\n<p><span style=\"color: #000000;\">Lorsque les ondes sont en phase ,les interf\u00e9rences sont constructives.<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-210 size-full alignnone\" src=\"http:\/\/yb-isn.fr\/2021\/spc\/wp-content\/uploads\/2021\/09\/sinusphase.png\" alt=\"\" width=\"621\" height=\"305\" srcset=\"https:\/\/yb-isn.fr\/2021\/spc\/wp-content\/uploads\/2021\/09\/sinusphase.png 621w, https:\/\/yb-isn.fr\/2021\/spc\/wp-content\/uploads\/2021\/09\/sinusphase-300x147.png 300w\" sizes=\"(max-width: 621px) 100vw, 621px\" \/><\/p>\n<p><span style=\"color: #ff0000;\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-70\" src=\"http:\/\/yb-isn.fr\/num\/wp-content\/uploads\/2019\/09\/retenir-e1569656528481.jpg\" alt=\"\" width=\"55\" height=\"55\"><\/span><span style=\"color: #000000;\">Si les deux ondes sont en phase au point M alors les interf\u00e9rences sont constructives.<\/span><\/p>\n<p><span style=\"color: #000000;\">Dans ce cas l&rsquo;amplitude de l&rsquo;onde r\u00e9sultante est maximale<\/span><\/p>\n<p><span style=\"color: #000000;\"><strong>\u03b4=k\u03bb &nbsp;&nbsp; avec k entier relatif<\/strong><\/span><\/p>\n<hr>\n<p><span style=\"color: #000000;\">Lorsque les ondes sont en opposition de phase<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-211 size-full alignnone\" src=\"http:\/\/yb-isn.fr\/2021\/spc\/wp-content\/uploads\/2021\/09\/sinusoppose.png\" alt=\"\" width=\"621\" height=\"307\" srcset=\"https:\/\/yb-isn.fr\/2021\/spc\/wp-content\/uploads\/2021\/09\/sinusoppose.png 621w, https:\/\/yb-isn.fr\/2021\/spc\/wp-content\/uploads\/2021\/09\/sinusoppose-300x148.png 300w\" sizes=\"(max-width: 621px) 100vw, 621px\" \/><\/p>\n<p><span style=\"color: #ff0000;\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-70\" src=\"http:\/\/yb-isn.fr\/num\/wp-content\/uploads\/2019\/09\/retenir-e1569656528481.jpg\" alt=\"\" width=\"55\" height=\"55\"><span style=\"color: #000000;\">Si les deux ondes sont en opposition de phase au point M alors les interf\u00e9rences sont destructives. <\/span><\/span><\/p>\n<p><span style=\"color: #000000;\">Dans ce cas l&rsquo;amplitude de l&rsquo;onde r\u00e9sultante est minimale.<\/span><\/p>\n<p><span style=\"color: #000000;\"><strong>\u03b4=(k+1\/2)\u03bb&nbsp;&nbsp;&nbsp; avec k entier relatif<\/strong><\/span><\/p>\n<p><a href=\"https:\/\/colab.research.google.com\/drive\/1e4IN_Q2jvhZLPZ2AOLR67uwGN7D-JunM?usp=sharing\">script python qui a permis obtenir et de visualiser&nbsp; la somme de deux sinuso\u00efdes<\/a><\/p>\n<p><span style=\"color: #000000;\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-54\" src=\"http:\/\/yb-isn.fr\/num\/wp-content\/uploads\/2019\/09\/activit\u00e9.png\" alt=\"\" width=\"55\" height=\"40\"><\/span><\/p>\n<p><span style=\"color: #000000;\">EXERCICE : Deux ondes coh\u00e9rentes de longueur d&rsquo;onde 2cm se propagent \u00e0 la surface de l&rsquo;eau.Elles arrivent en un m\u00eame point avec une diff\u00e9rence de marche&nbsp; d.<\/span><\/p>\n<p><span style=\"color: #000000;\"> Quel sont les ph\u00e9nom\u00e8nes observ\u00e9s dans chacun des cas. <\/span><\/p>\n<p><span style=\"color: #000000;\"> a) d=6 cm ; b) d= 9 cm ; c) d= 11 cm ; d) d= 12 cm<\/span><\/p>\n\n<div class=\"container theme1\" style=\"width:100%; height:auto\"><ul class=\"responsive-accordion responsive-accordion-default bm-larger\"><li><div class=\"responsive-accordion-head\" style=\"background-color:\"><span style=\"color:;font-size:15px\">correction<\/span><i class=\"fa fa-chevron-down responsive-accordion-plus fa-fw\"><\/i><i class=\"fa fa-chevron-up responsive-accordion-minus fa-fw\"><\/i><\/div><div class=\"responsive-accordion-panel\"style=\"background-color:;padding:12px;color:;font-size:14px\"><p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-237 size-full\" src=\"http:\/\/yb-isn.fr\/2021\/spc\/wp-content\/uploads\/2021\/10\/Capture-decran-2021-10-08-121912.png\" alt=\"\" width=\"827\" height=\"605\" srcset=\"https:\/\/yb-isn.fr\/2021\/spc\/wp-content\/uploads\/2021\/10\/Capture-decran-2021-10-08-121912.png 827w, https:\/\/yb-isn.fr\/2021\/spc\/wp-content\/uploads\/2021\/10\/Capture-decran-2021-10-08-121912-300x219.png 300w, https:\/\/yb-isn.fr\/2021\/spc\/wp-content\/uploads\/2021\/10\/Capture-decran-2021-10-08-121912-768x562.png 768w\" sizes=\"(max-width: 827px) 100vw, 827px\" \/><\/p>\n<\/div><\/li><\/ul><\/div>\n\n\n\n<p>activit\u00e9 3 page 462 : interf\u00e9rence dans une cuve \u00e0 onde<\/p>\n\n\n<div class=\"container theme1\" style=\"width:100%; height:auto\"><ul class=\"responsive-accordion responsive-accordion-default bm-larger\"><li><div class=\"responsive-accordion-head\" style=\"background-color:\"><span style=\"color:;font-size:15px\">corrig\u00e9<\/span><i class=\"fa fa-chevron-down responsive-accordion-plus fa-fw\"><\/i><i class=\"fa fa-chevron-up responsive-accordion-minus fa-fw\"><\/i><\/div><div class=\"responsive-accordion-panel\"style=\"background-color:;padding:12px;color:;font-size:14px\"><p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-271 size-full\" src=\"http:\/\/yb-isn.fr\/2021\/spc\/wp-content\/uploads\/2021\/10\/corrigeact3.png\" alt=\"\" width=\"956\" height=\"796\" srcset=\"https:\/\/yb-isn.fr\/2021\/spc\/wp-content\/uploads\/2021\/10\/corrigeact3.png 956w, https:\/\/yb-isn.fr\/2021\/spc\/wp-content\/uploads\/2021\/10\/corrigeact3-300x250.png 300w, https:\/\/yb-isn.fr\/2021\/spc\/wp-content\/uploads\/2021\/10\/corrigeact3-768x639.png 768w\" sizes=\"(max-width: 956px) 100vw, 956px\" \/><\/p>\n<\/div><\/li><\/ul><\/div>\n\n\n\n<p class=\"has-cyan-bluish-gray-background-color has-background has-medium-font-size\">2b) Cas des ondes lumineuses<\/p>\n\n\n\n<p>voir TP \u00b05<\/p>\n\n\n\n<figure class=\"wp-block-embed is-type-wp-embed is-provider-specialite-physique-chimie wp-block-embed-specialite-physique-chimie\"><div class=\"wp-block-embed__wrapper\">\n<blockquote class=\"wp-embedded-content\" data-secret=\"YxWTUVNRfZ\"><a href=\"https:\/\/yb-isn.fr\/2021\/spc\/?p=171\">TP n\u00b05 interf\u00e9rences<\/a><\/blockquote><iframe loading=\"lazy\" class=\"wp-embedded-content\" sandbox=\"allow-scripts\" security=\"restricted\" style=\"position: absolute; clip: rect(1px, 1px, 1px, 1px);\" title=\"\u00ab\u00a0TP n\u00b05 interf\u00e9rences\u00a0\u00bb &#8212; Sp\u00e9cialit\u00e9 Physique-Chimie\" src=\"https:\/\/yb-isn.fr\/2021\/spc\/?p=171&#038;embed=true#?secret=K7Ulvkar7F#?secret=YxWTUVNRfZ\" data-secret=\"YxWTUVNRfZ\" width=\"600\" height=\"338\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\"><\/iframe>\n<\/div><\/figure>\n\n\n\n<figure class=\"wp-block-gallery has-nested-images columns-default is-cropped wp-block-gallery-2 is-layout-flex wp-block-gallery-is-layout-flex\">\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" data-id=\"143\" src=\"http:\/\/yb-isn.fr\/ts42019\/wp-content\/uploads\/2019\/10\/interferences2.png\" alt=\"\" class=\"wp-image-143\"\/><\/figure>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" data-id=\"144\" src=\"http:\/\/yb-isn.fr\/ts42019\/wp-content\/uploads\/2019\/10\/interferences1.png\" alt=\"\" class=\"wp-image-144\"\/><\/figure>\n<\/figure>\n\n\n\n<p>L&rsquo;interfrange i ou distance entre deux franges sombres ou deux franges brillantes a pour expression<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"165\" height=\"95\" src=\"http:\/\/yb-isn.fr\/2021\/spc\/wp-content\/uploads\/2021\/10\/image.png\" alt=\"\" class=\"wp-image-193\"\/><\/figure>\n\n\n\n<p>exercice<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"852\" height=\"443\" src=\"http:\/\/yb-isn.fr\/2021\/spc\/wp-content\/uploads\/2021\/10\/image-1.png\" alt=\"\" class=\"wp-image-204\" srcset=\"https:\/\/yb-isn.fr\/2021\/spc\/wp-content\/uploads\/2021\/10\/image-1.png 852w, https:\/\/yb-isn.fr\/2021\/spc\/wp-content\/uploads\/2021\/10\/image-1-300x156.png 300w, https:\/\/yb-isn.fr\/2021\/spc\/wp-content\/uploads\/2021\/10\/image-1-768x399.png 768w\" sizes=\"(max-width: 852px) 100vw, 852px\" \/><\/figure>\n\n\n\n<p class=\"has-very-dark-gray-color has-cyan-bluish-gray-background-color has-text-color has-background has-large-font-size\">3)Niveau d&rsquo;intensit\u00e9 sonore<\/p>\n\n\n\n<p class=\"has-cyan-bluish-gray-background-color has-background\">3-a) Intensit\u00e9 sonore<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" src=\"http:\/\/yb-isn.fr\/spe-physique-2020\/wp-content\/uploads\/2020\/10\/Capture-d\u2019\u00e9cran-2020-10-11-135147.png\" alt=\"\" class=\"wp-image-319\"\/><\/figure>\n\n\n\n<p>La puissance est une \u00e9nergie par unit\u00e9 de temps.<\/p>\n\n\n\n<p>Elle s&rsquo;exprime donc en Joule par seconde qui correspond au Watt  (W)<\/p>\n\n\n\n<p class=\"has-cyan-bluish-gray-background-color has-background\">3-b) Niveau d&rsquo;intensit\u00e9 sonore<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" src=\"http:\/\/yb-isn.fr\/spe-physique-2020\/wp-content\/uploads\/2020\/10\/Capture-d\u2019\u00e9cran-2020-10-11-135049.png\" alt=\"\" class=\"wp-image-321\"\/><\/figure>\n\n\n\n<p>Exercice<\/p>\n\n\n\n<p>D\u00e9terminer les niveaux sonores en dB correspondants au seuil d&rsquo;audibilit\u00e9 et au seuil de douleur<\/p>\n\n\n\n<p><\/p>\n\n\n\n<p>Probl\u00e8me ouvert<\/p>\n\n\n\n<p>la voix d&rsquo;un choriste est entendue \u00e0 une distance d avec un niveau sonore de 60 dB.<\/p>\n\n\n\n<p>Combien de choristes faut il placer \u00e0 cette m\u00eame distance pour atteindre le seuil de douleur.<\/p>\n\n\n\n<p>indication \u00e0 retenir :<\/p>\n\n\n\n<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/yb-isn.fr\/num\/wp-content\/uploads\/2019\/09\/retenir-e1569656528481.jpg\" alt=\"\" width=\"55\" height=\"55\">Les intensit\u00e9s s&rsquo;ajoutent mais pas les niveaux sonores.<\/p>\n\n\n\n<p>Lorsqu&rsquo;on double l&rsquo;intensit\u00e9 sonore on ajoute 3 dB au niveau acoustique.<\/p>\n\n\n\n<p>aide math\u00e9matique<\/p>\n\n\n\n<figure class=\"wp-block-embed is-type-wp-embed is-provider-specialite-physique-chimie wp-block-embed-specialite-physique-chimie\"><div class=\"wp-block-embed__wrapper\">\n<blockquote class=\"wp-embedded-content\" data-secret=\"QevPZdBVhI\"><a href=\"https:\/\/yb-isn.fr\/2021\/spc\/?page_id=199\">logarithme d\u00e9cimal<\/a><\/blockquote><iframe loading=\"lazy\" class=\"wp-embedded-content\" sandbox=\"allow-scripts\" security=\"restricted\" style=\"position: absolute; clip: rect(1px, 1px, 1px, 1px);\" title=\"\u00ab\u00a0logarithme d\u00e9cimal\u00a0\u00bb &#8212; Sp\u00e9cialit\u00e9 Physique-Chimie\" src=\"https:\/\/yb-isn.fr\/2021\/spc\/?page_id=199&#038;embed=true#?secret=wBaq9omxXA#?secret=QevPZdBVhI\" data-secret=\"QevPZdBVhI\" width=\"600\" height=\"338\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\"><\/iframe>\n<\/div><\/figure>\n\n\n\n<p class=\"has-cyan-bluish-gray-background-color has-background\">3-c) Att\u00e9nuation <\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" src=\"http:\/\/yb-isn.fr\/spe-physique-2020\/wp-content\/uploads\/2020\/10\/Capture-d\u2019\u00e9cran-2020-10-11-143024.png\" alt=\"\" class=\"wp-image-324\"\/><\/figure>\n\n\n\n<video controls=\"\" width=\"320\" height=\"240\">\n  <source src=\"http:\/\/yb-isn.fr\/video-spe-phy\/li.mp4\" type=\"video\/mp4\">\n<\/video>\n","protected":false},"excerpt":{"rendered":"","protected":false},"author":1,"featured_media":126,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[],"class_list":["post-117","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-cours"],"_links":{"self":[{"href":"https:\/\/yb-isn.fr\/2021\/spc\/index.php?rest_route=\/wp\/v2\/posts\/117"}],"collection":[{"href":"https:\/\/yb-isn.fr\/2021\/spc\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/yb-isn.fr\/2021\/spc\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/yb-isn.fr\/2021\/spc\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/yb-isn.fr\/2021\/spc\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=117"}],"version-history":[{"count":46,"href":"https:\/\/yb-isn.fr\/2021\/spc\/index.php?rest_route=\/wp\/v2\/posts\/117\/revisions"}],"predecessor-version":[{"id":1102,"href":"https:\/\/yb-isn.fr\/2021\/spc\/index.php?rest_route=\/wp\/v2\/posts\/117\/revisions\/1102"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/yb-isn.fr\/2021\/spc\/index.php?rest_route=\/wp\/v2\/media\/126"}],"wp:attachment":[{"href":"https:\/\/yb-isn.fr\/2021\/spc\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=117"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/yb-isn.fr\/2021\/spc\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=117"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/yb-isn.fr\/2021\/spc\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=117"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}