Exercices sur le mouvement de translation F3
Exercice 1
On pousse une caisse de poids P = 400 N, de A vers D, selon le trajet ABCD. Le parcours horizontal CD a pour
longueur L = 4 m. La caisse est soumise à une force de frottement f, d'intensité constante f= 50 N, opposé à
tout instant au vecteur vitesse du point M.
1) Calculer :
a) Le travail W() effectué par le poids P de la caisse le long du trajet ABCD:
b) Le travail W(F) de la force de frottement sur le même trajet.
2) Calculer pour le trajet en ligne AD;
a) Le travail W (P) du poids P
b) Le travail WF) de la force de frottement *
c) Conclure. On donne : a = 30° ; B = 45° H = 3 m et h = 1m
B
A А
H
С

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