{"id":2238,"date":"2018-01-05T00:47:22","date_gmt":"2018-01-04T23:47:22","guid":{"rendered":"http:\/\/humm.loverde.fr\/?p=2238"},"modified":"2019-08-01T07:24:38","modified_gmt":"2019-08-01T06:24:38","slug":"vitesse-du-signal-dans-un-passage-a-niveau","status":"publish","type":"post","link":"https:\/\/humm.loverde.fr\/?p=2238","title":{"rendered":"Vitesse du signal dans un passage \u00e0 niveau"},"content":{"rendered":"

Vitesse du signal dans un passage \u00e0 niveau<\/p>\n

L’accident entre un train et un car rempli d’\u00e9l\u00e8ves qui a eu lieu dans le sud \u00e0 soulev\u00e9 beaucoup de col\u00e8re mais aussi beaucoup de fake News, le terme est arriv\u00e9 sur la place publique avec le futur projet de loi. Malheureusement cette loi n’emp\u00eachera pas les abonn\u00e9s de facebook qui se prennent pour des journalistes, de transmettre \u00e0 qui mieux mieux, et ils ne risqueront rien puisqu’ils ne seront pas la source \u00e0 l’origine de la fausse nouvelle!<\/p>\n

Je m’\u00e9gare…<\/p>\n

\"\"<\/p>\n

Vous avez peut-\u00eatre vu cette vid\u00e9o qui voit passer un train sans faire baisser la barri\u00e8re, vid\u00e9o qui date d’un autre temps et d’un autre lieu.<\/p>\n

\u00c0 ce propos la vitesse du signal transmis aux barri\u00e8res par le train qui arrive est-elle suffisante par rapport \u00e0 celle du train ou non, ce qui expliquerai les dysfonctionnements?
\nJ’ai souvenir de m’\u00eatre pos\u00e9 la question dans mon pass\u00e9 pas si lointain de prof de physique, \u00e0 quelle vitesse se d\u00e9placent les Porteurs de charges \u00e9lectriques dans un conducteur, j’avais trouv\u00e9 \u00e0 l’\u00e9poque qu’ils se d\u00e9pla\u00e7aient \u00e0 environ 50 cm par heure.<\/p>\n

La vitesse \u00e0 laquelle se d\u00e9place le signal \u00e9lectrique, donc l’\u00e9nergie \u00e9lectrique, correspond en r\u00e9alit\u00e9 \u00e0 la vitesse de propagation d’une onde \u00e9lectromagn\u00e9tique, et non pas \u00e0 la vitesse de d\u00e9placement des charges \u00e9lectriques. La propagation de cette onde est tr\u00e8s rapide. Dans un circuit en cuivre, elle est g\u00e9n\u00e9ralement comprise entre 175 000 et 200 000 km\/s.<\/p>\n

La vitesse de d\u00e9placement moyenne des charges due \u00e0 la diff\u00e9rence de potentiel appliqu\u00e9e est beaucoup plus lente, quelques centim\u00e8tres par heure dans un fil de cuivre.<\/p>\n

Merci qui? merci wiki(p\u00e9dia)<\/p>\n

 <\/p>\n\n\n\n
\"\"<\/a><\/td>\n\"sig?u=ChristianLoverde\"Christian Loverde
\nhttps:\/\/humm.loverde.fr<\/a><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n","protected":false},"excerpt":{"rendered":"

Vitesse du signal dans un passage \u00e0 niveau L’accident entre un train et un car rempli d’\u00e9l\u00e8ves qui a eu … <\/p>\n","protected":false},"author":1,"featured_media":2239,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"jetpack_post_was_ever_published":false},"categories":[13],"tags":[991,993,990,992],"class_list":["post-2238","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-actuel","tag-passage-a-niveau","tag-signal","tag-train","tag-vitesse"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/i0.wp.com\/humm.loverde.fr\/wp-content\/uploads\/2018\/01\/Attachment-1-2.png?fit=644%2C322&ssl=1","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p9whbF-A6","jetpack_likes_enabled":true,"jetpack-related-posts":[{"id":7881,"url":"https:\/\/humm.loverde.fr\/?p=7881","url_meta":{"origin":2238,"position":0},"title":"Pub du mec qui s’incruste un Lego dans le pied","author":"cloverde","date":"29 septembre 2022","format":false,"excerpt":"Et visiblement \u00e7a fait mal mais pas au point de renoncer \u00e0 ces c\u00e9l\u00e8bres c\u00e9r\u00e9ales hyper sucr\u00e9es. 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