{"id":680,"date":"2021-04-27T14:14:55","date_gmt":"2021-04-27T12:14:55","guid":{"rendered":"https:\/\/mxth.dk\/?p=680"},"modified":"2026-04-09T22:13:56","modified_gmt":"2026-04-09T20:13:56","slug":"fjederkraefter","status":"publish","type":"post","link":"https:\/\/mxth.dk\/?p=680","title":{"rendered":"Fjederkr\u00e6fter"},"content":{"rendered":"\n<p class=\" eplus-wrapper\">Vi skal arbejde lidt med fjederkr\u00e6fter og se lidt p\u00e5 hvordan de opf\u00f8rer sig. Vi har set p\u00e5, at en fjeder kan f\u00f8lge Hooke,s lov som er <\/p>\n\n\n\n<p class=\" has-text-align-center eplus-wrapper\"><img decoding=\"async\" src=\"https:\/\/s0.wp.com\/latex.php?latex=F_%7Bfjeder%7D%3D-k%5Ccdot+x&#038;bg=ffffff&#038;fg=000&#038;s=0&#038;c=20201002\" alt=\"F_{fjeder}=-k&#92;cdot x\" class=\"latex\" \/>,<\/p>\n\n\n\n<p class=\" eplus-wrapper\">hvor k er fjederkonstanten og x er forskydningen. <\/p>\n\n\n\n<p class=\" eplus-wrapper\">Vi skal her bruge en simulator til at unders\u00f8ge egenskaberne ved en fjeder. Form\u00e5let er her, at vi<\/p>\n\n\n<ul class=\"eplus-wrapper wp-block-list eplus-styles-uid-0df25a\">\n<li class=\" eplus-wrapper\">validere Hooke\u2019s lov<\/li>\n\n\n\n<li class=\" eplus-wrapper\">bruger Hooke\u2019s lov til at bestemme en ukendt passe og en ukendt v\u00e6rdi for tyngdeaccelerationen<\/li>\n\n\n\n<li class=\" eplus-wrapper\">analysere, hvordan forskellige kombinationer af fjedre p\u00e5virker udvidelsen af et system<\/li>\n<\/ul>\n\n\n<p class=\" eplus-wrapper\"><\/p>\n\n\n\n<p class=\" eplus-wrapper\">Til at validere Hooke\u2019s lov bruger vi simulatoren her under. Der er fire valgmuligheder og vi benytter den der hedder \u201c<em>Lab<\/em>\u201d. Under simulationen er opgaven listet i punktform.<\/p>\n\n\n\n<iframe loading=\"lazy\" src=\"https:\/\/phet.colorado.edu\/sims\/html\/masses-and-springs\/latest\/masses-and-springs_en.html\" scrolling=\"no\" allowfullscreen=\"\" width=\"800\" height=\"600\"><\/iframe>\n\n\n\n<h5 class=\" wp-block-heading eplus-wrapper\">Del 1 &#8211; validering af Hooke\u2019s lov<\/h5>\n\n\n<ol class=\"eplus-wrapper wp-block-list eplus-styles-uid-8e20da\">\n<li class=\" eplus-wrapper\">Placer et lod p\u00e5 100g for enden af fjederen. Fjederen vil nu begynde, at svinge op og ned. For at undg\u00e5, at fjederen svinger for meget op og ned \u00f8ger vi d\u00e6mpningen (<em>Dampning<\/em>) ude til h\u00f8jere til max (<em>Lots<\/em>)<\/li>\n\n\n\n<li class=\" eplus-wrapper\">Klik p\u00e5 valgmulighederne \u201c<em>Displacement<\/em>\u201d og \u201c<em>Movable Line<\/em>\u201d oppe i h\u00f8jere hj\u00f8rne. Den bl\u00e5 linje svare til fjederens l\u00e6ngde n\u00e5r der ikke er v\u00e6gt p\u00e5. Du kan nu placere den r\u00f8de linje s\u00e5 den for enden af den gr\u00f8nne pil som indikere hvor langt fjederen er udstrukket. <\/li>\n<\/ol>\n\n\n<figure class=\" wp-block-image aligncenter size-large eplus-wrapper\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" width=\"468\" height=\"460\" src=\"https:\/\/i0.wp.com\/mxth.dk\/wp-content\/uploads\/2021\/04\/7B4DAEB1-26CF-4FEA-B394-FA9B7D66F2D9.jpeg?resize=468%2C460&#038;ssl=1\" alt=\"\" class=\"wp-image-689\" srcset=\"https:\/\/i0.wp.com\/mxth.dk\/wp-content\/uploads\/2021\/04\/7B4DAEB1-26CF-4FEA-B394-FA9B7D66F2D9.jpeg?w=468&amp;ssl=1 468w, https:\/\/i0.wp.com\/mxth.dk\/wp-content\/uploads\/2021\/04\/7B4DAEB1-26CF-4FEA-B394-FA9B7D66F2D9.jpeg?resize=300%2C295&amp;ssl=1 300w\" sizes=\"auto, (max-width: 468px) 100vw, 468px\" \/><\/figure>\n\n\n<ol start=\"3\" class=\"eplus-wrapper wp-block-list eplus-styles-uid-54c2a9\">\n<li class=\" eplus-wrapper\">Brug linealv\u00e6rkt\u00f8jet ude til h\u00f8jre (<strong>HUSK<\/strong> enheder) til, at m\u00e5le udstr\u00e6kningen af fjederen med den 100 grams masse. Konverter massen til en kraft (brug <img decoding=\"async\" src=\"https:\/\/s0.wp.com\/latex.php?latex=g%3D9%2C82+ms%5E%7B-2%7D&#038;bg=ffffff&#038;fg=000&#038;s=0&#038;c=20201002\" alt=\"g=9,82 ms^{-2}\" class=\"latex\" \/>) og noter det i en tabel som vist i tabel 1. <strong>HUSK<\/strong> at omregn gram til kilogram!<\/li>\n<\/ol>\n\n\n<figure class=\" wp-block-table eplus-wrapper\"><table><tbody><tr><td class=\"has-text-align-center\" data-align=\"center\"><strong>Masse tilf\u00f8rt fjederen (g)<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\"><strong>Kraft (N)<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\"><strong>Udstr\u00e6kning (mm)<\/strong><\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\">100 g<\/td><td class=\"has-text-align-center\" data-align=\"center\"><\/td><td class=\"has-text-align-center\" data-align=\"center\"><\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\"><\/td><td class=\"has-text-align-center\" data-align=\"center\"><\/td><td class=\"has-text-align-center\" data-align=\"center\"><\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\"><\/td><td class=\"has-text-align-center\" data-align=\"center\"><\/td><td class=\"has-text-align-center\" data-align=\"center\"><\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\"><\/td><td class=\"has-text-align-center\" data-align=\"center\"><\/td><td class=\"has-text-align-center\" data-align=\"center\"><\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\"><\/td><td class=\"has-text-align-center\" data-align=\"center\"><\/td><td class=\"has-text-align-center\" data-align=\"center\"><\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\"><\/td><td class=\"has-text-align-center\" data-align=\"center\"><\/td><td class=\"has-text-align-center\" data-align=\"center\"><\/td><\/tr><\/tbody><\/table><figcaption class=\"wp-element-caption\">Tabel 1 &#8211; lav en tabel magen til denne og noter dine data ned i den.<\/figcaption><\/figure>\n\n\n<ol start=\"4\" class=\"eplus-wrapper wp-block-list eplus-styles-uid-0e713f\">\n<li class=\" eplus-wrapper\">Brug nu skyderen i toppen til at \u00e6ndre massen af loddet og noter yderligere 5 datapunkter ned og noter dem i tabel 1.<\/li>\n<\/ol>\n\n\n<figure class=\" wp-block-image aligncenter size-large eplus-wrapper\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" width=\"498\" height=\"244\" src=\"https:\/\/i0.wp.com\/mxth.dk\/wp-content\/uploads\/2021\/04\/1EAB0F2F-E98D-4CCF-B208-9AF0E6723016.jpeg?resize=498%2C244&#038;ssl=1\" alt=\"\" class=\"wp-image-690\" srcset=\"https:\/\/i0.wp.com\/mxth.dk\/wp-content\/uploads\/2021\/04\/1EAB0F2F-E98D-4CCF-B208-9AF0E6723016.jpeg?w=498&amp;ssl=1 498w, https:\/\/i0.wp.com\/mxth.dk\/wp-content\/uploads\/2021\/04\/1EAB0F2F-E98D-4CCF-B208-9AF0E6723016.jpeg?resize=300%2C147&amp;ssl=1 300w\" sizes=\"auto, (max-width: 498px) 100vw, 498px\" \/><\/figure>\n\n\n<ol start=\"5\" class=\"eplus-wrapper wp-block-list eplus-styles-uid-40a2e0\">\n<li class=\" eplus-wrapper\">Plot en graf (fx. i Excel eller GeoGebra), hvor kraften er op ad 2.-aksen og udstr\u00e6kningen er langs 1.-aksen. Tegn den bedste rette linje gennem dine punkter.<\/li>\n\n\n\n<li class=\" eplus-wrapper\">Brug grafen til, at bestemme fjederkonstanten for din fjeder (i <img decoding=\"async\" src=\"https:\/\/s0.wp.com\/latex.php?latex=Nmm%5E%7B-1%7D&#038;bg=ffffff&#038;fg=000&#038;s=0&#038;c=20201002\" alt=\"Nmm^{-1}\" class=\"latex\" \/>) ved at finde h\u00e6ldningen.<\/li>\n\n\n\n<li class=\" eplus-wrapper\">Hvilket bevis har du fra din graf som fort\u00e6ller at fjederen overholder Hooke\u2019s lov?<\/li>\n<\/ol>\n\n\n<h5 class=\" wp-block-heading eplus-wrapper\">Del 2 &#8211; Bestemme st\u00f8rrelsen af en ukendt masse.<\/h5>\n\n\n\n<p class=\" eplus-wrapper\">Brug din v\u00e6rdi for fjederkonstanten som du fandt i del 1 til at bestemme massen af to ukendte masser (en r\u00f8d og en bl\u00e5) i simulationen. Vis, hvordan du har gjort og hvilke m\u00e5linger du har foretaget til denne del af opgaven. For at f\u00e5 en god gennemsnitsmasse, s\u00e5 skal der foretages minimum tre m\u00e5linger til hver masse.<\/p>\n\n\n\n<figure class=\" wp-block-image aligncenter size-large eplus-wrapper\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" width=\"488\" height=\"284\" src=\"https:\/\/i0.wp.com\/mxth.dk\/wp-content\/uploads\/2021\/04\/A7D46019-EFB5-4A28-B47E-978350CFC95B.jpeg?resize=488%2C284&#038;ssl=1\" alt=\"\" class=\"wp-image-691\" srcset=\"https:\/\/i0.wp.com\/mxth.dk\/wp-content\/uploads\/2021\/04\/A7D46019-EFB5-4A28-B47E-978350CFC95B.jpeg?w=488&amp;ssl=1 488w, https:\/\/i0.wp.com\/mxth.dk\/wp-content\/uploads\/2021\/04\/A7D46019-EFB5-4A28-B47E-978350CFC95B.jpeg?resize=300%2C175&amp;ssl=1 300w\" sizes=\"auto, (max-width: 488px) 100vw, 488px\" \/><\/figure>\n\n\n\n<p class=\" eplus-wrapper\">Den r\u00f8de masse = \u2026\u2026.. g<br>Den bl\u00e5 masse = \u2026\u2026\u2026.. g<\/p>\n\n\n\n<h5 class=\" wp-block-heading eplus-wrapper\">Del 3 &#8211; bestemme en ukendt v\u00e6rdi for tyngdekraft<\/h5>\n\n\n\n<p class=\" eplus-wrapper\">\u00c6ndre tyngdekraft (<em>Gravity<\/em>) til \u201cPlanet X\u201d<\/p>\n\n\n\n<figure class=\" wp-block-image aligncenter size-large eplus-wrapper\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" width=\"567\" height=\"302\" src=\"https:\/\/i0.wp.com\/mxth.dk\/wp-content\/uploads\/2021\/04\/53684AE2-2B8B-44A2-929E-5D295F47CCE9.jpeg?resize=567%2C302&#038;ssl=1\" alt=\"\" class=\"wp-image-692\" srcset=\"https:\/\/i0.wp.com\/mxth.dk\/wp-content\/uploads\/2021\/04\/53684AE2-2B8B-44A2-929E-5D295F47CCE9.jpeg?w=567&amp;ssl=1 567w, https:\/\/i0.wp.com\/mxth.dk\/wp-content\/uploads\/2021\/04\/53684AE2-2B8B-44A2-929E-5D295F47CCE9.jpeg?resize=300%2C160&amp;ssl=1 300w\" sizes=\"auto, (max-width: 567px) 100vw, 567px\" \/><\/figure>\n\n\n\n<p class=\" eplus-wrapper\">V\u00e6rdien af g er nu ikke l\u00e6ngere <img decoding=\"async\" src=\"https:\/\/s0.wp.com\/latex.php?latex=9.8+ms%5E%7B-2%7D&#038;bg=ffffff&#038;fg=000&#038;s=0&#038;c=20201002\" alt=\"9.8 ms^{-2}\" class=\"latex\" \/>, men en ukendt v\u00e6rdi.<\/p>\n\n\n\n<p class=\" eplus-wrapper\">Brug fjederkonstanten fra del 1, til at bestemme den ukendte v\u00e6rdi af g for denne planet. Vis igen, hvordan du har gjort og hvilke m\u00e5linger du har foretaget til denne del af opgaven. For at f\u00e5 en god gennemsnitsmasse, s\u00e5 skal der foretages minimum tre m\u00e5linger til hver masse.<\/p>\n\n\n\n<p class=\" eplus-wrapper\">Ukendt g = \u2026\u2026\u2026. <img decoding=\"async\" src=\"https:\/\/s0.wp.com\/latex.php?latex=ms%5E%7B-2%7D&#038;bg=ffffff&#038;fg=000&#038;s=0&#038;c=20201002\" alt=\"ms^{-2}\" class=\"latex\" \/><\/p>\n\n\n\n<hr class=\" wp-block-separator has-css-opacity eplus-wrapper\"\/>\n\n\n\n<h5 class=\" wp-block-heading eplus-wrapper\">Del 4 &#8211; kombination af fjedre<\/h5>\n\n\n\n<p class=\" eplus-wrapper\">Vi vil nu benytte en anden simulator til at unders\u00f8ge, hvordan et system af fjedre opf\u00f8rer sig. Til dette benyttes simulationen herunder, hvor vi benytter den midterste som hedder \u201c<em>Systems<\/em>\u201d. Igen er opgaven opstillet i punktform under simulationen.<\/p>\n\n\n\n<iframe loading=\"lazy\" src=\"https:\/\/phet.colorado.edu\/sims\/html\/hookes-law\/latest\/hookes-law_en.html\" scrolling=\"no\" allowfullscreen=\"\" width=\"800\" height=\"600\"><\/iframe>\n\n\n<ol class=\"eplus-wrapper wp-block-list eplus-styles-uid-266dba\">\n<li class=\" eplus-wrapper\">Klik p\u00e5 valgmulighederne \u201c<em>Displacement<\/em>\u201d, \u201c<em>Equilibrium Position<\/em>\u201d og \u201c<em>Values<\/em>\u201d.  Tjek at muligheden af to fjedre i parallel er valgt s\u00e5ledes at fjedrene ser ud som p\u00e5 billedet herunder.<\/li>\n<\/ol>\n\n\n<figure class=\"wp-block-gallery has-nested-images columns-default is-cropped eplus-wrapper wp-block-gallery-1\">\n<figure class=\" wp-block-image size-large eplus-wrapper\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"450\" data-id=\"698\" src=\"https:\/\/i0.wp.com\/mxth.dk\/wp-content\/uploads\/2021\/04\/FE11A9E2-2783-4300-B79D-2B2E4A5665C1.jpeg?resize=1024%2C450&#038;ssl=1\" alt=\"\" class=\"wp-image-698\" srcset=\"https:\/\/i0.wp.com\/mxth.dk\/wp-content\/uploads\/2021\/04\/FE11A9E2-2783-4300-B79D-2B2E4A5665C1.jpeg?resize=1024%2C450&amp;ssl=1 1024w, https:\/\/i0.wp.com\/mxth.dk\/wp-content\/uploads\/2021\/04\/FE11A9E2-2783-4300-B79D-2B2E4A5665C1.jpeg?resize=300%2C132&amp;ssl=1 300w, https:\/\/i0.wp.com\/mxth.dk\/wp-content\/uploads\/2021\/04\/FE11A9E2-2783-4300-B79D-2B2E4A5665C1.jpeg?resize=768%2C338&amp;ssl=1 768w, https:\/\/i0.wp.com\/mxth.dk\/wp-content\/uploads\/2021\/04\/FE11A9E2-2783-4300-B79D-2B2E4A5665C1.jpeg?resize=1536%2C676&amp;ssl=1 1536w, https:\/\/i0.wp.com\/mxth.dk\/wp-content\/uploads\/2021\/04\/FE11A9E2-2783-4300-B79D-2B2E4A5665C1.jpeg?resize=1568%2C690&amp;ssl=1 1568w, https:\/\/i0.wp.com\/mxth.dk\/wp-content\/uploads\/2021\/04\/FE11A9E2-2783-4300-B79D-2B2E4A5665C1.jpeg?w=2014&amp;ssl=1 2014w\" sizes=\"auto, (max-width: 1000px) 100vw, 1000px\" \/><\/figure>\n\n\n\n<figure class=\" wp-block-image size-large eplus-wrapper\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" width=\"656\" height=\"1024\" data-id=\"699\" src=\"https:\/\/i0.wp.com\/mxth.dk\/wp-content\/uploads\/2021\/04\/F3A40BB2-05C7-4326-9FB2-7956701E2C51.jpeg?resize=656%2C1024&#038;ssl=1\" alt=\"\" class=\"wp-image-699\" srcset=\"https:\/\/i0.wp.com\/mxth.dk\/wp-content\/uploads\/2021\/04\/F3A40BB2-05C7-4326-9FB2-7956701E2C51.jpeg?resize=656%2C1024&amp;ssl=1 656w, https:\/\/i0.wp.com\/mxth.dk\/wp-content\/uploads\/2021\/04\/F3A40BB2-05C7-4326-9FB2-7956701E2C51.jpeg?resize=192%2C300&amp;ssl=1 192w, https:\/\/i0.wp.com\/mxth.dk\/wp-content\/uploads\/2021\/04\/F3A40BB2-05C7-4326-9FB2-7956701E2C51.jpeg?w=713&amp;ssl=1 713w\" sizes=\"auto, (max-width: 656px) 100vw, 656px\" \/><\/figure>\n<figcaption class=\"blocks-gallery-caption wp-element-caption\">Fjedre i parallel<\/figcaption><\/figure>\n\n\n<ol start=\"2\" class=\"eplus-wrapper wp-block-list eplus-styles-uid-efe8bf\">\n<li class=\" eplus-wrapper\">S\u00e6t  fjederkonstanten for den \u00f8verste fjeder til <img decoding=\"async\" src=\"https:\/\/s0.wp.com\/latex.php?latex=k_1%3D200Nm%5E%7B-1%7D&#038;bg=ffffff&#038;fg=000&#038;s=0&#038;c=20201002\" alt=\"k_1=200Nm^{-1}\" class=\"latex\" \/> og den nederste fjederkonstant til <img decoding=\"async\" src=\"https:\/\/s0.wp.com\/latex.php?latex=k_2%3D200Nm%5E%7B-1%7D&#038;bg=ffffff&#038;fg=000&#038;s=0&#038;c=20201002\" alt=\"k_2=200Nm^{-1}\" class=\"latex\" \/>. Tilf\u00f8r fjederen en kraft p\u00e5 100N mod h\u00f8jre. M\u00e5l forskydelsen og bestem den totale fjederkonstant for de to fjedre i parallel. Noter dine resultater i tabel 2.<\/li>\n<\/ol>\n\n\n<figure class=\" wp-block-table eplus-wrapper\"><table><tbody><tr><td><img decoding=\"async\" src=\"https:\/\/s0.wp.com\/latex.php?latex=k_1%7B%7D%28Nm%5E%7B-1%7D%29&#038;bg=ffffff&#038;fg=000&#038;s=0&#038;c=20201002\" alt=\"k_1{}(Nm^{-1})\" class=\"latex\" \/><\/td><td><img decoding=\"async\" src=\"https:\/\/s0.wp.com\/latex.php?latex=k_1%7B%7D%28Nm%5E%7B-1%7D%29&#038;bg=ffffff&#038;fg=000&#038;s=0&#038;c=20201002\" alt=\"k_1{}(Nm^{-1})\" class=\"latex\" \/><\/td><td>Kraft (N)<\/td><td>Udstr\u00e6kning (m)<\/td><td>Total <img decoding=\"async\" src=\"https:\/\/s0.wp.com\/latex.php?latex=k%7B%7D%28Nm%5E%7B-1%7D%29&#038;bg=ffffff&#038;fg=000&#038;s=0&#038;c=20201002\" alt=\"k{}(Nm^{-1})\" class=\"latex\" \/><\/td><\/tr><tr><td><\/td><td><\/td><td>100 N<\/td><td><\/td><td><\/td><\/tr><tr><td><\/td><td><\/td><td>100 N<\/td><td><\/td><td><\/td><\/tr><tr><td><\/td><td><\/td><td>100 N<\/td><td><\/td><td><\/td><\/tr><tr><td><\/td><td><\/td><td>100 N<\/td><td><\/td><td><\/td><\/tr><\/tbody><\/table><figcaption class=\"wp-element-caption\">Tabel 2 &#8211; to fjedre i parallel<\/figcaption><\/figure>\n\n\n<ol start=\"3\" class=\"eplus-wrapper wp-block-list eplus-styles-uid-0f11da\">\n<li class=\" eplus-wrapper\">Gentag forrige trin tre gange mere ved at \u00e6ndre p\u00e5 v\u00e6rdierne for <img decoding=\"async\" src=\"https:\/\/s0.wp.com\/latex.php?latex=k_1&#038;bg=ffffff&#038;fg=000&#038;s=0&#038;c=20201002\" alt=\"k_1\" class=\"latex\" \/> og <img decoding=\"async\" src=\"https:\/\/s0.wp.com\/latex.php?latex=k_2&#038;bg=ffffff&#038;fg=000&#038;s=0&#038;c=20201002\" alt=\"k_2\" class=\"latex\" \/> og noter dem i tabel 2.<\/li>\n\n\n\n<li class=\" eplus-wrapper\">Beskriv forholdet mellem de individuelle fjederkonstanter <img decoding=\"async\" src=\"https:\/\/s0.wp.com\/latex.php?latex=k_1&#038;bg=ffffff&#038;fg=000&#038;s=0&#038;c=20201002\" alt=\"k_1\" class=\"latex\" \/> og <img decoding=\"async\" src=\"https:\/\/s0.wp.com\/latex.php?latex=k_2&#038;bg=ffffff&#038;fg=000&#038;s=0&#038;c=20201002\" alt=\"k_2\" class=\"latex\" \/>, og den totale fjederkonstant <img decoding=\"async\" src=\"https:\/\/s0.wp.com\/latex.php?latex=k&#038;bg=ffffff&#038;fg=000&#038;s=0&#038;c=20201002\" alt=\"k\" class=\"latex\" \/> for fjederen i parallel. Pr\u00f8v om ikke du kan opskrive en sammenh\u00e6ng i form af en ligning.<\/li>\n\n\n\n<li class=\" eplus-wrapper\">V\u00e6lg nu mulighed for fjedrene i serie s\u00e5ledes at fjedrene nu er i en kombination som ses p\u00e5 billedet herunder.<\/li>\n<\/ol>\n\n\n<figure class=\"wp-block-gallery has-nested-images columns-default is-cropped eplus-wrapper wp-block-gallery-2\">\n<figure class=\" wp-block-image size-large eplus-wrapper\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"270\" data-id=\"701\" src=\"https:\/\/i0.wp.com\/mxth.dk\/wp-content\/uploads\/2021\/04\/08A676B9-DFF6-4EEE-8920-3C3874577FFA.jpeg?resize=1024%2C270&#038;ssl=1\" alt=\"\" class=\"wp-image-701\" srcset=\"https:\/\/i0.wp.com\/mxth.dk\/wp-content\/uploads\/2021\/04\/08A676B9-DFF6-4EEE-8920-3C3874577FFA.jpeg?resize=1024%2C270&amp;ssl=1 1024w, https:\/\/i0.wp.com\/mxth.dk\/wp-content\/uploads\/2021\/04\/08A676B9-DFF6-4EEE-8920-3C3874577FFA.jpeg?resize=300%2C79&amp;ssl=1 300w, https:\/\/i0.wp.com\/mxth.dk\/wp-content\/uploads\/2021\/04\/08A676B9-DFF6-4EEE-8920-3C3874577FFA.jpeg?resize=768%2C202&amp;ssl=1 768w, https:\/\/i0.wp.com\/mxth.dk\/wp-content\/uploads\/2021\/04\/08A676B9-DFF6-4EEE-8920-3C3874577FFA.jpeg?resize=1536%2C404&amp;ssl=1 1536w, https:\/\/i0.wp.com\/mxth.dk\/wp-content\/uploads\/2021\/04\/08A676B9-DFF6-4EEE-8920-3C3874577FFA.jpeg?resize=1568%2C413&amp;ssl=1 1568w, https:\/\/i0.wp.com\/mxth.dk\/wp-content\/uploads\/2021\/04\/08A676B9-DFF6-4EEE-8920-3C3874577FFA.jpeg?w=2010&amp;ssl=1 2010w\" sizes=\"auto, (max-width: 1000px) 100vw, 1000px\" \/><\/figure>\n\n\n\n<figure class=\" wp-block-image size-large eplus-wrapper\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" width=\"709\" height=\"214\" data-id=\"702\" src=\"https:\/\/i0.wp.com\/mxth.dk\/wp-content\/uploads\/2021\/04\/EAAB3A65-31AA-4500-BA5B-42E24E98FB03.jpeg?resize=709%2C214&#038;ssl=1\" alt=\"\" class=\"wp-image-702\" srcset=\"https:\/\/i0.wp.com\/mxth.dk\/wp-content\/uploads\/2021\/04\/EAAB3A65-31AA-4500-BA5B-42E24E98FB03.jpeg?w=709&amp;ssl=1 709w, https:\/\/i0.wp.com\/mxth.dk\/wp-content\/uploads\/2021\/04\/EAAB3A65-31AA-4500-BA5B-42E24E98FB03.jpeg?resize=300%2C91&amp;ssl=1 300w\" sizes=\"auto, (max-width: 709px) 100vw, 709px\" \/><\/figure>\n<figcaption class=\"blocks-gallery-caption wp-element-caption\">Fjedre i serie<\/figcaption><\/figure>\n\n\n<ol start=\"4\" class=\"eplus-wrapper wp-block-list eplus-styles-uid-d6d560\">\n<li class=\" eplus-wrapper\">S\u00e6t den vestre fjederkonstant til <img decoding=\"async\" src=\"https:\/\/s0.wp.com\/latex.php?latex=k_1%3D400+Nm%5E%7B-1%7D&#038;bg=ffffff&#038;fg=000&#038;s=0&#038;c=20201002\" alt=\"k_1=400 Nm^{-1}\" class=\"latex\" \/> og den h\u00f8jre fjederkonstant <img decoding=\"async\" src=\"https:\/\/s0.wp.com\/latex.php?latex=k_2%3D400+Nm%5E%7B-1%7D&#038;bg=ffffff&#038;fg=000&#038;s=0&#038;c=20201002\" alt=\"k_2=400 Nm^{-1}\" class=\"latex\" \/>. Tilf\u00f8r nu fjederen en kraft p\u00e5 100 N mod h\u00f8jre. M\u00e5l forskydningen og bestem den totale fjederkonstant k af de to fjedre i serie. Noter dine resultater i tabel 3<\/li>\n<\/ol>\n\n\n<figure class=\" wp-block-table eplus-wrapper\"><table><tbody><tr><td><img decoding=\"async\" src=\"https:\/\/s0.wp.com\/latex.php?latex=k_1%7B%7D%28Nm%5E%7B-1%7D%29&#038;bg=ffffff&#038;fg=000&#038;s=0&#038;c=20201002\" alt=\"k_1{}(Nm^{-1})\" class=\"latex\" \/><\/td><td><img decoding=\"async\" src=\"https:\/\/s0.wp.com\/latex.php?latex=k_1%7B%7D%28Nm%5E%7B-1%7D%29&#038;bg=ffffff&#038;fg=000&#038;s=0&#038;c=20201002\" alt=\"k_1{}(Nm^{-1})\" class=\"latex\" \/><\/td><td>Kraft (N)<\/td><td>Udstr\u00e6kning (m)<\/td><td>Total <img decoding=\"async\" src=\"https:\/\/s0.wp.com\/latex.php?latex=k%7B%7D%28Nm%5E%7B-1%7D%29&#038;bg=ffffff&#038;fg=000&#038;s=0&#038;c=20201002\" alt=\"k{}(Nm^{-1})\" class=\"latex\" \/><\/td><\/tr><tr><td><\/td><td><\/td><td>100 N<\/td><td><\/td><td><\/td><\/tr><tr><td><\/td><td><\/td><td>100 N<\/td><td><\/td><td><\/td><\/tr><tr><td><\/td><td><\/td><td>100 N<\/td><td><\/td><td><\/td><\/tr><tr><td><\/td><td><\/td><td>100 N<\/td><td><\/td><td><\/td><\/tr><\/tbody><\/table><figcaption class=\"wp-element-caption\">Tabel 3 &#8211; to fjedre i serie<\/figcaption><\/figure>\n\n\n<ol start=\"5\" class=\"eplus-wrapper wp-block-list eplus-styles-uid-2e2f5f\">\n<li class=\" eplus-wrapper\">Gentag forrige trin yderligere tre gange ved at \u00e6ndre p\u00e5 v\u00e6rdierne for <img decoding=\"async\" src=\"https:\/\/s0.wp.com\/latex.php?latex=k_1&#038;bg=ffffff&#038;fg=000&#038;s=0&#038;c=20201002\" alt=\"k_1\" class=\"latex\" \/> og <img decoding=\"async\" src=\"https:\/\/s0.wp.com\/latex.php?latex=k_2&#038;bg=ffffff&#038;fg=000&#038;s=0&#038;c=20201002\" alt=\"k_2\" class=\"latex\" \/> og noter resultatet i tabel 3.<\/li>\n\n\n\n<li class=\" eplus-wrapper\">Tre elever har hver et bud p\u00e5 en model til at finde den totale fjederkonstant k for to fjedre i serie, forklar hvilken elevs model der er korrekt baseret p\u00e5 dine resultater<ul class=\"eplus-wrapper wp-block-list eplus-styles-uid-305d2f\">\n<li class=\" eplus-wrapper\">elev 1: <img decoding=\"async\" src=\"https:\/\/s0.wp.com\/latex.php?latex=k%3D%5Cfrac%7Bk_1%2Bk_2%7D%7Bk_1k_2%7D&#038;bg=ffffff&#038;fg=000&#038;s=0&#038;c=20201002\" alt=\"k=&#92;frac{k_1+k_2}{k_1k_2}\" class=\"latex\" \/><\/li>\n\n\n\n<li class=\" eplus-wrapper\">elev 2: <img decoding=\"async\" src=\"https:\/\/s0.wp.com\/latex.php?latex=k%3D%5Cfrac%7B%28k_1%2Bk_2%29%5E2%7D%7Bk_1%2Bk_2%7D&#038;bg=ffffff&#038;fg=000&#038;s=0&#038;c=20201002\" alt=\"k=&#92;frac{(k_1+k_2)^2}{k_1+k_2}\" class=\"latex\" \/><\/li>\n\n\n\n<li class=\" eplus-wrapper\">elev 3: <img decoding=\"async\" src=\"https:\/\/s0.wp.com\/latex.php?latex=%5Cfrac%7B1%7D%7Bk%7D%3D%5Cfrac%7B1%7D%7Bk_1%7D%2B%5Cfrac%7B1%7D%7Bk_2%7D&#038;bg=ffffff&#038;fg=000&#038;s=0&#038;c=20201002\" alt=\"&#92;frac{1}{k}=&#92;frac{1}{k_1}+&#92;frac{1}{k_2}\" class=\"latex\" \/><\/li>\n<\/ul><\/li>\n<\/ol>","protected":false},"excerpt":{"rendered":"<p>Vi skal arbejde lidt med fjederkr\u00e6fter og se lidt p\u00e5 hvordan de opf\u00f8rer sig. Vi har set p\u00e5, at en fjeder kan f\u00f8lge Hooke,s lov som er , hvor k er fjederkonstanten og x er forskydningen. Vi skal her bruge en simulator til at unders\u00f8ge egenskaberne ved en fjeder. Form\u00e5let er her, at vi Til [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"ub_ctt_via":"","editor_plus_copied_stylings":"{}","_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_post_was_ever_published":false},"categories":[26,2],"tags":[],"class_list":["post-680","post","type-post","status-publish","format-standard","hentry","category-fjederkraefter","category-fysik"],"featured_image_src":null,"author_info":{"display_name":"Henriksen","author_link":"https:\/\/mxth.dk\/?author=1"},"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/mxth.dk\/index.php?rest_route=\/wp\/v2\/posts\/680","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mxth.dk\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mxth.dk\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mxth.dk\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/mxth.dk\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=680"}],"version-history":[{"count":18,"href":"https:\/\/mxth.dk\/index.php?rest_route=\/wp\/v2\/posts\/680\/revisions"}],"predecessor-version":[{"id":3386,"href":"https:\/\/mxth.dk\/index.php?rest_route=\/wp\/v2\/posts\/680\/revisions\/3386"}],"wp:attachment":[{"href":"https:\/\/mxth.dk\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=680"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mxth.dk\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=680"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mxth.dk\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=680"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}