Ecrit par ✅ Quiz : Postulats D Einstein
Ce quiz contient 20 questions.
Note : Placeholder pour valider la structure. Le JSON converti est conservé ci-dessous pour l’import final des vraies questions Tutor LMS.
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{
"quiz_title": "Postulats D Einstein",
"quiz_slug": "02_postulats_d_einstein_quiz",
"quiz_description": "Quiz Edu509 : Postulats D Einstein",
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"questions": [
{
"question_order": 1,
"question_title": "Quel est le premier postulat de la relativité restreinte d’Einstein ?",
"question_type": "single_choice",
"question_mark": 1,
"answer_required": true,
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"question_description": "",
"question_explanation": "Le premier postulat affirme que les lois de la physique sont identiques dans tous les référentiels inertiels, sans référentiel privilégié.",
"answers": [
{
"answer_title": "Les lois de la physique sont les mêmes dans tous les référentiels inertiels.",
"is_correct": true,
"answer_order": 1
},
{
"answer_title": "La vitesse de la lumière dépend du mouvement de la source.",
"is_correct": false,
"answer_order": 2
},
{
"answer_title": "Le temps est absolu pour tous les observateurs.",
"is_correct": false,
"answer_order": 3
},
{
"answer_title": "La masse d’un objet ne change jamais.",
"is_correct": false,
"answer_order": 4
}
]
},
{
"question_order": 2,
"question_title": "Quelle est la valeur de la vitesse de la lumière dans le vide selon le deuxième postulat d’Einstein ?",
"question_type": "single_choice",
"question_mark": 1,
"answer_required": true,
"randomize_question": false,
"show_question_mark": true,
"question_description": "",
"question_explanation": "La vitesse de la lumière dans le vide est toujours \\\\( 3{,}00 \\\\times 10^8 \\\\mathrm{m/s} \\\\), quelle que soit la vitesse de la source ou de l’observateur.",
"answers": [
{
"answer_title": "\\\\( 3{,}00 \\\\times 10^8 \\\\mathrm{m/s} \\\\)",
"is_correct": true,
"answer_order": 1
},
{
"answer_title": "\\\\( 1{,}50 \\\\times 10^8 \\\\mathrm{m/s} \\\\)",
"is_correct": false,
"answer_order": 2
},
{
"answer_title": "\\\\( 9{,}81 \\\\mathrm{m/s^2} \\\\)",
"is_correct": false,
"answer_order": 3
},
{
"answer_title": "\\\\( 2{,}99 \\\\times 10^7 \\\\mathrm{m/s} \\\\)",
"is_correct": false,
"answer_order": 4
}
]
},
{
"question_order": 3,
"question_title": "Un vaisseau se déplace à \\\\( v = 2{,}4 \\\\times 10^8 \\\\mathrm{m/s} \\\\). Quelle est la valeur du facteur de Lorentz \\\\( \\\\gamma \\\\) ?",
"question_type": "single_choice",
"question_mark": 1,
"answer_required": true,
"randomize_question": false,
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"question_description": "",
"question_explanation": "On a \\\\( \\\\gamma = \\\\frac{1}{\\\\sqrt{1 - (2{,}4/3{,}00)^2}} = \\\\frac{1}{0{,}6} = 1,67 \\\\).",
"answers": [
{
"answer_title": "1,67",
"is_correct": true,
"answer_order": 1
},
{
"answer_title": "2,01",
"is_correct": false,
"answer_order": 2
},
{
"answer_title": "0,80",
"is_correct": false,
"answer_order": 3
},
{
"answer_title": "1,25",
"is_correct": false,
"answer_order": 4
}
]
},
{
"question_order": 4,
"question_title": "Un train de longueur propre \\\\( L_0 = 300 \\\\mathrm{m} \\\\) se déplace à \\\\( v = 2{,}6 \\\\times 10^8 \\\\mathrm{m/s} \\\\). Quelle longueur mesure un observateur fixe ?",
"question_type": "single_choice",
"question_mark": 1,
"answer_required": true,
"randomize_question": false,
"show_question_mark": true,
"question_description": "",
"question_explanation": "La contraction donne \\\\( L = \\\\frac{300}{2,01} \\\\approx 149,3 \\\\mathrm{m} \\\\).",
"answers": [
{
"answer_title": "149,3 m",
"is_correct": true,
"answer_order": 1
},
{
"answer_title": "300 m",
"is_correct": false,
"answer_order": 2
},
{
"answer_title": "200 m",
"is_correct": false,
"answer_order": 3
},
{
"answer_title": "75 m",
"is_correct": false,
"answer_order": 4
}
]
},
{
"question_order": 5,
"question_title": "Dans la transformation de Lorentz, quelle est l’expression correcte pour \\\\( t' \\\\) ?",
"question_type": "single_choice",
"question_mark": 1,
"answer_required": true,
"randomize_question": false,
"show_question_mark": true,
"question_description": "",
"question_explanation": "La transformation correcte pour le temps est \\\\( t' = \\\\gamma \\\\left(t - \\\\frac{vx}{c^2}\\\\right) \\\\).",
"answers": [
{
"answer_title": "\\\\( t' = \\\\gamma \\\\left(t - \\\\frac{vx}{c^2}\\\\right) \\\\)",
"is_correct": true,
"answer_order": 1
},
{
"answer_title": "\\\\( t' = \\\\gamma (t + vx) \\\\)",
"is_correct": false,
"answer_order": 2
},
{
"answer_title": "\\\\( t' = t - \\\\gamma vx \\\\)",
"is_correct": false,
"answer_order": 3
},
{
"answer_title": "\\\\( t' = \\\\gamma (t - vx) \\\\)",
"is_correct": false,
"answer_order": 4
}
]
},
{
"question_order": 6,
"question_title": "Un muon voyage à \\\\( v = 0{,}995c \\\\) avec une durée de vie propre \\\\( 2{,}2 \\\\times 10^{-6} \\\\mathrm{s} \\\\). Quelle durée de vie mesure un observateur terrestre ?",
"question_type": "single_choice",
"question_mark": 1,
"answer_required": true,
"randomize_question": false,
"show_question_mark": true,
"question_description": "",
"question_explanation": "La dilatation du temps donne \\\\( \\\\Delta t = 10,01 \\\\times 2{,}2 \\\\times 10^{-6} = 2{,}20 \\\\times 10^{-5} \\\\mathrm{s} \\\\).",
"answers": [
{
"answer_title": "\\\\( 2{,}20 \\\\times 10^{-5} \\\\mathrm{s} \\\\)",
"is_correct": true,
"answer_order": 1
},
{
"answer_title": "\\\\( 2{,}2 \\\\times 10^{-6} \\\\mathrm{s} \\\\)",
"is_correct": false,
"answer_order": 2
},
{
"answer_title": "\\\\( 1{,}0 \\\\times 10^{-5} \\\\mathrm{s} \\\\)",
"is_correct": false,
"answer_order": 3
},
{
"answer_title": "\\\\( 1{,}1 \\\\times 10^{-5} \\\\mathrm{s} \\\\)",
"is_correct": false,
"answer_order": 4
}
]
},
{
"question_order": 7,
"question_title": "Pour un objet se déplaçant à \\\\( v = 0{,}9c \\\\), quel est le facteur de contraction des longueurs \\\\( \\\\gamma \\\\) ?",
"question_type": "single_choice",
"question_mark": 1,
"answer_required": true,
"randomize_question": false,
"show_question_mark": true,
"question_description": "",
"question_explanation": "Pour \\\\( v = 0{,}9c \\\\), \\\\( \\\\gamma = \\\\frac{1}{\\\\sqrt{1 - 0,81}} = 2,29 \\\\).",
"answers": [
{
"answer_title": "2,29",
"is_correct": true,
"answer_order": 1
},
{
"answer_title": "1,67",
"is_correct": false,
"answer_order": 2
},
{
"answer_title": "1,00",
"is_correct": false,
"answer_order": 3
},
{
"answer_title": "0,90",
"is_correct": false,
"answer_order": 4
}
]
},
{
"question_order": 8,
"question_title": "Un astronaute voyage à \\\\( v = 0{,}9c \\\\) vers une étoile distante de \\\\( 9,0 \\\\mathrm{al} \\\\). Quelle distance mesure-t-il ?",
"question_type": "single_choice",
"question_mark": 1,
"answer_required": true,
"randomize_question": false,
"show_question_mark": true,
"question_description": "",
"question_explanation": "La contraction donne \\\\( L = \\\\frac{9,0}{2,29} = 3,93 \\\\mathrm{al} \\\\).",
"answers": [
{
"answer_title": "3,93 al",
"is_correct": true,
"answer_order": 1
},
{
"answer_title": "9,0 al",
"is_correct": false,
"answer_order": 2
},
{
"answer_title": "6,00 al",
"is_correct": false,
"answer_order": 3
},
{
"answer_title": "2,29 al",
"is_correct": false,
"answer_order": 4
}
]
},
{
"question_order": 9,
"question_title": "Quelles affirmations sont vraies concernant la simultanéité en relativité restreinte ?",
"question_type": "single_choice",
"question_mark": 1,
"answer_required": true,
"randomize_question": false,
"show_question_mark": true,
"question_description": "",
"question_explanation": "La simultanéité dépend du référentiel ; ce qui est simultané pour un observateur ne l’est pas forcément pour un autre.",
"answers": [
{
"answer_title": "Deux événements simultanés dans un référentiel peuvent ne pas l’être dans un autre.",
"is_correct": true,
"answer_order": 1
},
{
"answer_title": "La simultanéité est absolue pour tous les observateurs.",
"is_correct": false,
"answer_order": 2
},
{
"answer_title": "La vitesse de la lumière dépend de la simultanéité.",
"is_correct": false,
"answer_order": 3
},
{
"answer_title": "La simultanéité n’a pas d’importance en relativité.",
"is_correct": false,
"answer_order": 4
}
]
},
{
"question_order": 10,
"question_title": "Quelle est la définition d’un référentiel inertiel ?",
"question_type": "single_choice",
"question_mark": 1,
"answer_required": true,
"randomize_question": false,
"show_question_mark": true,
"question_description": "",
"question_explanation": "Un référentiel inertiel est un référentiel en mouvement rectiligne uniforme où les lois de la physique gardent leur forme simple.",
"answers": [
{
"answer_title": "Un référentiel où les lois de la physique s’appliquent sous forme simple et sans force fictive.",
"is_correct": true,
"answer_order": 1
},
{
"answer_title": "Un référentiel accéléré.",
"is_correct": false,
"answer_order": 2
},
{
"answer_title": "Un référentiel attaché à la Terre uniquement.",
"is_correct": false,
"answer_order": 3
},
{
"answer_title": "Un référentiel où la vitesse de la lumière varie.",
"is_correct": false,
"answer_order": 4
}
]
},
{
"question_order": 11,
"question_title": "Si une horloge mesure \\\\( \\\\Delta t_0 = 1,0 \\\\mathrm{s} \\\\) dans son propre référentiel et se déplace à \\\\( v = 2{,}4 \\\\times 10^8 \\\\mathrm{m/s} \\\\), quelle durée mesure un observateur fixe ?",
"question_type": "single_choice",
"question_mark": 1,
"answer_required": true,
"randomize_question": false,
"show_question_mark": true,
"question_description": "",
"question_explanation": "La dilatation du temps donne \\\\( \\\\Delta t = 1,67 \\\\times 1,0 = 1,67 \\\\mathrm{s} \\\\).",
"answers": [
{
"answer_title": "1,67 s",
"is_correct": true,
"answer_order": 1
},
{
"answer_title": "1,00 s",
"is_correct": false,
"answer_order": 2
},
{
"answer_title": "2,01 s",
"is_correct": false,
"answer_order": 3
},
{
"answer_title": "0,60 s",
"is_correct": false,
"answer_order": 4
}
]
},
{
"question_order": 12,
"question_title": "Quelle propriété exprime la covariance en relativité restreinte ?",
"question_type": "single_choice",
"question_mark": 1,
"answer_required": true,
"randomize_question": false,
"show_question_mark": true,
"question_description": "",
"question_explanation": "La covariance signifie que les lois physiques conservent leur forme dans tous les référentiels inertiels.",
"answers": [
{
"answer_title": "Les lois physiques gardent la même forme dans tous les référentiels inertiels.",
"is_correct": true,
"answer_order": 1
},
{
"answer_title": "La vitesse de la lumière varie selon le référentiel.",
"is_correct": false,
"answer_order": 2
},
{
"answer_title": "La masse est invariante.",
"is_correct": false,
"answer_order": 3
},
{
"answer_title": "Le temps est absolu.",
"is_correct": false,
"answer_order": 4
}
]
},
{
"question_order": 13,
"question_title": "Dans la contraction des longueurs, quelle grandeur reste invariante ?",
"question_type": "single_choice",
"question_mark": 1,
"answer_required": true,
"randomize_question": false,
"show_question_mark": true,
"question_description": "",
"question_explanation": "La longueur propre \\\\( L_0 \\\\) est mesurée dans le référentiel où l’objet est au repos et reste invariante dans ce référentiel.",
"answers": [
{
"answer_title": "La longueur propre \\\\( L_0 \\\\)",
"is_correct": true,
"answer_order": 1
},
{
"answer_title": "La longueur mesurée dans le référentiel en mouvement",
"is_correct": false,
"answer_order": 2
},
{
"answer_title": "La durée mesurée dans le référentiel fixe",
"is_correct": false,
"answer_order": 3
},
{
"answer_title": "La vitesse de l’objet",
"is_correct": false,
"answer_order": 4
}
]
},
{
"question_order": 14,
"question_title": "Quelle est la conséquence directe du deuxième postulat d’Einstein ?",
"question_type": "single_choice",
"question_mark": 1,
"answer_required": true,
"randomize_question": false,
"show_question_mark": true,
"question_description": "",
"question_explanation": "Le deuxième postulat affirme que la vitesse de la lumière dans le vide est constante pour tous les observateurs.",
"answers": [
{
"answer_title": "La vitesse de la lumière est la même pour tous les observateurs.",
"is_correct": true,
"answer_order": 1
},
{
"answer_title": "Le temps est identique pour tous.",
"is_correct": false,
"answer_order": 2
},
{
"answer_title": "La masse ne varie jamais.",
"is_correct": false,
"answer_order": 3
},
{
"answer_title": "La longueur ne change pas avec la vitesse.",
"is_correct": false,
"answer_order": 4
}
]
},
{
"question_order": 15,
"question_title": "Un objet se déplace à \\\\( v = 0,8c \\\\). Quelle est la valeur de \\\\( \\\\gamma \\\\) ?",
"question_type": "single_choice",
"question_mark": 1,
"answer_required": true,
"randomize_question": false,
"show_question_mark": true,
"question_description": "",
"question_explanation": "Pour \\\\( v = 0,8c \\\\), \\\\( \\\\gamma = \\\\frac{1}{\\\\sqrt{1 - 0,64}} = 1,67 \\\\).",
"answers": [
{
"answer_title": "1,67",
"is_correct": true,
"answer_order": 1
},
{
"answer_title": "2,29",
"is_correct": false,
"answer_order": 2
},
{
"answer_title": "1,25",
"is_correct": false,
"answer_order": 3
},
{
"answer_title": "0,80",
"is_correct": false,
"answer_order": 4
}
]
},
{
"question_order": 16,
"question_title": "Quelle formule exprime la dilatation du temps ?",
"question_type": "single_choice",
"question_mark": 1,
"answer_required": true,
"randomize_question": false,
"show_question_mark": true,
"question_description": "",
"question_explanation": "La dilatation du temps est donnée par \\\\( \\\\Delta t = \\\\gamma \\\\Delta t_0 \\\\).",
"answers": [
{
"answer_title": "\\\\( \\\\Delta t = \\\\gamma \\\\Delta t_0 \\\\)",
"is_correct": true,
"answer_order": 1
},
{
"answer_title": "\\\\( \\\\Delta t = \\\\frac{\\\\Delta t_0}{\\\\gamma} \\\\)",
"is_correct": false,
"answer_order": 2
},
{
"answer_title": "\\\\( \\\\Delta t_0 = \\\\gamma \\\\Delta t \\\\)",
"is_correct": false,
"answer_order": 3
},
{
"answer_title": "\\\\( \\\\Delta t = \\\\Delta t_0 \\\\)",
"is_correct": false,
"answer_order": 4
}
]
},
{
"question_order": 17,
"question_title": "Un objet de longueur propre \\\\( L_0 = 100 \\\\mathrm{m} \\\\) se déplace à \\\\( v = 0,6c \\\\). Quelle longueur mesure un observateur fixe ?",
"question_type": "single_choice",
"question_mark": 1,
"answer_required": true,
"randomize_question": false,
"show_question_mark": true,
"question_description": "",
"question_explanation": "Pour \\\\( v = 0,6c \\\\), \\\\( \\\\gamma = 1,25 \\\\), donc \\\\( L = \\\\frac{100}{1,25} = 80,0 \\\\mathrm{m} \\\\).",
"answers": [
{
"answer_title": "80,0 m",
"is_correct": true,
"answer_order": 1
},
{
"answer_title": "100 m",
"is_correct": false,
"answer_order": 2
},
{
"answer_title": "60,0 m",
"is_correct": false,
"answer_order": 3
},
{
"answer_title": "120 m",
"is_correct": false,
"answer_order": 4
}
]
},
{
"question_order": 18,
"question_title": "Dans la transformation de Lorentz, que représente \\\\( x' \\\\) ?",
"question_type": "single_choice",
"question_mark": 1,
"answer_required": true,
"randomize_question": false,
"show_question_mark": true,
"question_description": "",
"question_explanation": "Dans la transformation de Lorentz, \\\\( x' \\\\) est la position dans le référentiel en mouvement.",
"answers": [
{
"answer_title": "La position mesurée dans le référentiel en mouvement.",
"is_correct": true,
"answer_order": 1
},
{
"answer_title": "La position dans le référentiel fixe.",
"is_correct": false,
"answer_order": 2
},
{
"answer_title": "La durée propre.",
"is_correct": false,
"answer_order": 3
},
{
"answer_title": "La vitesse de la lumière.",
"is_correct": false,
"answer_order": 4
}
]
},
{
"question_order": 19,
"question_title": "Un événement se produit à \\\\( x = 600 \\\\mathrm{m} \\\\), \\\\( t = 2,0 \\\\mathrm{\\\\ s} \\\\), dans un référentiel où \\\\( v = 0,8c \\\\). Quelle est la valeur de \\\\( x' \\\\) ?",
"question_type": "single_choice",
"question_mark": 1,
"answer_required": true,
"randomize_question": false,
"show_question_mark": true,
"question_description": "",
"question_explanation": "Avec \\\\( \\\\gamma = 1,67 \\\\), \\\\( x' = \\\\gamma (x - vt) = 1,67 (600 - 0,8c \\\\times 2) = 1,67 (600 - 480) = 1,67 \\\\times 120 = 200 \\\\).",
"answers": [
{
"answer_title": "200 m",
"is_correct": true,
"answer_order": 1
},
{
"answer_title": "600 m",
"is_correct": false,
"answer_order": 2
},
{
"answer_title": "480 m",
"is_correct": false,
"answer_order": 3
},
{
"answer_title": "0 m",
"is_correct": false,
"answer_order": 4
}
]
},
{
"question_order": 20,
"question_title": "Pour un objet se déplaçant à \\\\( v = 0,6c \\\\), quelle est la valeur de \\\\( \\\\gamma \\\\) ?",
"question_type": "single_choice",
"question_mark": 1,
"answer_required": true,
"randomize_question": false,
"show_question_mark": true,
"question_description": "",
"question_explanation": "Pour \\\\( v = 0,6c \\\\), \\\\( \\\\gamma = \\\\frac{1}{\\\\sqrt{1 - 0,36}} = 1,25 \\\\).",
"answers": [
{
"answer_title": "1,25",
"is_correct": true,
"answer_order": 1
},
{
"answer_title": "1,67",
"is_correct": false,
"answer_order": 2
},
{
"answer_title": "2,00",
"is_correct": false,
"answer_order": 3
},
{
"answer_title": "0,60",
"is_correct": false,
"answer_order": 4
}
]
}
]
}