Quiz — 3AM-EX-ROTATION 2.pdf

Question 1 sur 5 10:00

[{"id":848,"question":"Quelle grandeur physique mesure la rapidité de rotation d'un objet ?","option_a":"Vitesse linéaire","option_b":"Vitesse angulaire","option_c":"Accélération","option_d":"Fréquence","option_e":"","option_f":"","bonne_reponse":"b","explication":"La vitesse angulaire (ω) mesure la rapidité de rotation en radians par seconde (rad\/s). Elle est liée à la fréquence (f) par la formule ω = 2πf.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"b\", \"options\": {\"a\": \"Vitesse linéaire\", \"b\": \"Vitesse angulaire\", \"c\": \"Accélératio","_debug_options_count":4},{"id":849,"question":"Si un disque tourne à une fréquence de 5 Hz, quelle est sa période ?","option_a":"0,2 s","option_b":"5 s","option_c":"0,5 s","option_d":"2 s","option_e":"","option_f":"","bonne_reponse":"a","explication":"La période T est l'inverse de la fréquence : T = 1\/f. Ici, T = 1\/5 = 0,2 seconde.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"a\", \"options\": {\"a\": \"0,2 s\", \"b\": \"5 s\", \"c\": \"0,5 s\", \"d\": \"2 s\"}}","_debug_options_count":4},{"id":850,"question":"Quelle formule relie la vitesse linéaire (v) à la vitesse angulaire (ω) pour un point situé à une distance r de l'axe de rotation ?","option_a":"v = ω × r","option_b":"v = ω \/ r","option_c":"v = r \/ ω","option_d":"v = ω + r","option_e":"","option_f":"","bonne_reponse":"a","explication":"La vitesse linéaire d'un point est donnée par v = ω × r, où ω est en rad\/s et r en mètres.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"a\", \"options\": {\"a\": \"v = ω × r\", \"b\": \"v = ω \/ r\", \"c\": \"v = r \/ ω\", \"d\": \"v = ω ","_debug_options_count":4},{"id":851,"question":"Un moteur tourne à 1200 tours par minute (tr\/min). Quelle est sa vitesse angulaire en rad\/s ?","option_a":"20π rad\/s","option_b":"40π rad\/s","option_c":"1200π rad\/s","option_d":"60π rad\/s","option_e":"","option_f":"","bonne_reponse":"b","explication":"Convertissez d'abord en Hz : 1200 tr\/min = 20 Hz. Puis ω = 2πf = 2π × 20 = 40π rad\/s.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"b\", \"options\": {\"a\": \"20π rad\/s\", \"b\": \"40π rad\/s\", \"c\": \"1200π rad\/s\", \"d\": \"60π r","_debug_options_count":4},{"id":852,"question":"Si un objet en rotation a une vitesse angulaire de 10 rad\/s, quelle est sa fréquence en Hz ?","option_a":"5 Hz","option_b":"10 Hz","option_c":"1,59 Hz","option_d":"0,16 Hz","option_e":"","option_f":"","bonne_reponse":"c","explication":"La fréquence f est donnée par f = ω \/ (2π). Ici, f = 10 \/ (2π) ≈ 1,59 Hz.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"c\", \"options\": {\"a\": \"5 Hz\", \"b\": \"10 Hz\", \"c\": \"1,59 Hz\", \"d\": \"0,16 Hz\"}}","_debug_options_count":4}]