Un cube est posé sur un plan incliné et relié à un fil attaché à un poteau.
On représente ci-dessous la situation :
{"init": {"range": [[-8.0, 8.0], [-3.0, 13.0]], "scale": [20, 20]}, "line": [[[-7.0, -2.0], [7.0, -2.0], {"subtype": "segment", "stroke": "#ccc"}], [[-7.0, -1.0], [7.0, -1.0], {"subtype": "segment", "stroke": "#ccc"}], [[-7.0, 0.0], [7.0, 0.0], {"subtype": "segment", "stroke": "#ccc"}], [[-7.0, 1.0], [7.0, 1.0], {"subtype": "segment", "stroke": "#ccc"}], [[-7.0, 2.0], [7.0, 2.0], {"subtype": "segment", "stroke": "#ccc"}], [[-7.0, 3.0], [7.0, 3.0], {"subtype": "segment", "stroke": "#ccc"}], [[-7.0, 4.0], [7.0, 4.0], {"subtype": "segment", "stroke": "#ccc"}], [[-7.0, 5.0], [7.0, 5.0], {"subtype": "segment", "stroke": "#ccc"}], [[-7.0, 6.0], [7.0, 6.0], {"subtype": "segment", "stroke": "#ccc"}], [[-7.0, 7.0], [7.0, 7.0], {"subtype": "segment", "stroke": "#ccc"}], [[-7.0, 8.0], [7.0, 8.0], {"subtype": "segment", "stroke": "#ccc"}], [[-7.0, 9.0], [7.0, 9.0], {"subtype": "segment", "stroke": "#ccc"}], [[-7.0, 10.0], [7.0, 10.0], {"subtype": "segment", "stroke": "#ccc"}], [[-7.0, 11.0], [7.0, 11.0], {"subtype": "segment", "stroke": "#ccc"}], [[-7.0, 12.0], [7.0, 12.0], {"subtype": "segment", "stroke": "#ccc"}], [[-7.0, -2.0], [-7.0, 12.0], {"subtype": "segment", "stroke": "#ccc"}], [[-6.0, -2.0], [-6.0, 12.0], {"subtype": "segment", "stroke": "#ccc"}], [[-5.0, -2.0], [-5.0, 12.0], {"subtype": "segment", "stroke": "#ccc"}], [[-4.0, -2.0], [-4.0, 12.0], {"subtype": "segment", "stroke": "#ccc"}], [[-3.0, -2.0], [-3.0, 12.0], {"subtype": "segment", "stroke": "#ccc"}], [[-2.0, -2.0], [-2.0, 12.0], {"subtype": "segment", "stroke": "#ccc"}], [[-1.0, -2.0], [-1.0, 12.0], {"subtype": "segment", "stroke": "#ccc"}], [[0.0, -2.0], [0.0, 12.0], {"subtype": "segment", "stroke": "#ccc"}], [[1.0, -2.0], [1.0, 12.0], {"subtype": "segment", "stroke": "#ccc"}], [[2.0, -2.0], [2.0, 12.0], {"subtype": "segment", "stroke": "#ccc"}], [[3.0, -2.0], [3.0, 12.0], {"subtype": "segment", "stroke": "#ccc"}], [[4.0, -2.0], [4.0, 12.0], {"subtype": "segment", "stroke": "#ccc"}], [[5.0, -2.0], [5.0, 12.0], {"subtype": "segment", "stroke": "#ccc"}], [[6.0, -2.0], [6.0, 12.0], {"subtype": "segment", "stroke": "#ccc"}], [[7.0, -2.0], [7.0, 12.0], {"subtype": "segment", "stroke": "#ccc"}], [[-1.1149412193707495, 5.503447097433675], [-0.11149412193707475, 6.618388316804424], {"subtype": "segment"}], [[-0.11149412193707475, 6.618388316804424], [2.118388316804424, 4.611494121937075], {"subtype": "segment"}], [[2.118388316804424, 4.611494121937075], [1.1149412193707495, 3.496552902566325], {"subtype": "segment"}], [[-5.0, 10.009021803530528], [-0.6132176706539121, 6.060917707119049], {"subtype": "segment"}], [[-5.0, 9.0], [-5.0, 11.0], {"subtype": "segment"}], [[5.0, 0.0], [-5.0, 9.0], {"subtype": "segment"}], [[-5.0, 0.0], [5.0, 0.0], {"subtype": "segment"}]], "arc": [[[5.0, 0.0], [1.5, 1.5], 138.0127875041833, 180.0, false, {}]], "circle": [[[0.5017235487168372, 5.0574706096853745], 0.1, {"fill": "black"}]], "label": [[[3.0, -0.5], "\\alpha", "above", {}], [[0.0017235487168372199, 4.5574706096853745], "G", "above", {}]]}
On considère à présent le solide comme un point pour effectuer le bilan des forces.
On représente la situation ci-dessous :
{"init": {"range": [[-7.0, 7.0], [-12.0, 7.0]], "scale": [40, 40]}, "line": [[[-6.0, -11.0], [6.0, -11.0], {"subtype": "segment", "stroke": "#ccc"}], [[-6.0, -10.0], [6.0, -10.0], {"subtype": "segment", "stroke": "#ccc"}], [[-6.0, -9.0], [6.0, -9.0], {"subtype": "segment", "stroke": "#ccc"}], [[-6.0, -8.0], [6.0, -8.0], {"subtype": "segment", "stroke": "#ccc"}], [[-6.0, -7.0], [6.0, -7.0], {"subtype": "segment", "stroke": "#ccc"}], [[-6.0, -6.0], [6.0, -6.0], {"subtype": "segment", "stroke": "#ccc"}], [[-6.0, -5.0], [6.0, -5.0], {"subtype": "segment", "stroke": "#ccc"}], [[-6.0, -4.0], [6.0, -4.0], {"subtype": "segment", "stroke": "#ccc"}], [[-6.0, -3.0], [6.0, -3.0], {"subtype": "segment", "stroke": "#ccc"}], [[-6.0, -2.0], [6.0, -2.0], {"subtype": "segment", "stroke": "#ccc"}], [[-6.0, -1.0], [6.0, -1.0], {"subtype": "segment", "stroke": "#ccc"}], [[-6.0, 0.0], [6.0, 0.0], {"subtype": "segment", "stroke": "#ccc"}], [[-6.0, 1.0], [6.0, 1.0], {"subtype": "segment", "stroke": "#ccc"}], [[-6.0, 2.0], [6.0, 2.0], {"subtype": "segment", "stroke": "#ccc"}], [[-6.0, 3.0], [6.0, 3.0], {"subtype": "segment", "stroke": "#ccc"}], [[-6.0, 4.0], [6.0, 4.0], {"subtype": "segment", "stroke": "#ccc"}], [[-6.0, 5.0], [6.0, 5.0], {"subtype": "segment", "stroke": "#ccc"}], [[-6.0, 6.0], [6.0, 6.0], {"subtype": "segment", "stroke": "#ccc"}], [[-6.0, -11.0], [-6.0, 6.0], {"subtype": "segment", "stroke": "#ccc"}], [[-5.0, -11.0], [-5.0, 6.0], {"subtype": "segment", "stroke": "#ccc"}], [[-4.0, -11.0], [-4.0, 6.0], {"subtype": "segment", "stroke": "#ccc"}], [[-3.0, -11.0], [-3.0, 6.0], {"subtype": "segment", "stroke": "#ccc"}], [[-2.0, -11.0], [-2.0, 6.0], {"subtype": "segment", "stroke": "#ccc"}], [[-1.0, -11.0], [-1.0, 6.0], {"subtype": "segment", "stroke": "#ccc"}], [[0.0, -11.0], [0.0, 6.0], {"subtype": "segment", "stroke": "#ccc"}], [[1.0, -11.0], [1.0, 6.0], {"subtype": "segment", "stroke": "#ccc"}], [[2.0, -11.0], [2.0, 6.0], {"subtype": "segment", "stroke": "#ccc"}], [[3.0, -11.0], [3.0, 6.0], {"subtype": "segment", "stroke": "#ccc"}], [[4.0, -11.0], [4.0, 6.0], {"subtype": "segment", "stroke": "#ccc"}], [[5.0, -11.0], [5.0, 6.0], {"subtype": "segment", "stroke": "#ccc"}], [[6.0, -11.0], [6.0, 6.0], {"subtype": "segment", "stroke": "#ccc"}], [[0.0, 0.0], [4.475138121546961, 4.972375690607736], {"subtype": "segment", "arrow-end": "classic-wide-long"}], [[0.0, 0.0], [-4.475138121546961, 4.027624309392264], {"subtype": "segment", "arrow-end": "classic-wide-long"}], [[0.0, 0.0], [0.0, -9.0], {"subtype": "segment", "arrow-end": "classic-wide-long"}]], "circle": [[[0.0, 0.0], 0.1, {"fill": "black"}]], "label": [[[0.0, 0.0], "G", "above", {}], [[2.6835455485217805, 2.0848090063303983], null], [[-2.63894789974695, 1.5678356669478322], null], [[0.6, -4.5], null], [[1.0, -5.5], "\\overrightarrow{\\rm P}", "above", {}], [[5.237569060773481, 1.486187845303868], "\\overrightarrow{\\rm R}", "above", {}], [[-1.7375690607734806, 2.013812154696132], "\\overrightarrow{\\rm T}", "above", {}]]}
Données
- - Accélération de la pesanteur : \( g = 9,81\:\text{m}\mathord{\cdot}\text{s}^{-2} \)
- - Masse du solide : \( m = 505\:\text{g} \)
En calculant graphiquement l'échelle des forces représentés, donner la valeur, en Newton (N), representée par 1
carreau.
On donnera la réponse avec \( 2 \) chiffres significatifs et suivie de l'unité qui convient.