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, 12.0]], "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, -2.0], [-7.0, 11.0], {"subtype": "segment", "stroke": "#ccc"}], [[-6.0, -2.0], [-6.0, 11.0], {"subtype": "segment", "stroke": "#ccc"}], [[-5.0, -2.0], [-5.0, 11.0], {"subtype": "segment", "stroke": "#ccc"}], [[-4.0, -2.0], [-4.0, 11.0], {"subtype": "segment", "stroke": "#ccc"}], [[-3.0, -2.0], [-3.0, 11.0], {"subtype": "segment", "stroke": "#ccc"}], [[-2.0, -2.0], [-2.0, 11.0], {"subtype": "segment", "stroke": "#ccc"}], [[-1.0, -2.0], [-1.0, 11.0], {"subtype": "segment", "stroke": "#ccc"}], [[0.0, -2.0], [0.0, 11.0], {"subtype": "segment", "stroke": "#ccc"}], [[1.0, -2.0], [1.0, 11.0], {"subtype": "segment", "stroke": "#ccc"}], [[2.0, -2.0], [2.0, 11.0], {"subtype": "segment", "stroke": "#ccc"}], [[3.0, -2.0], [3.0, 11.0], {"subtype": "segment", "stroke": "#ccc"}], [[4.0, -2.0], [4.0, 11.0], {"subtype": "segment", "stroke": "#ccc"}], [[5.0, -2.0], [5.0, 11.0], {"subtype": "segment", "stroke": "#ccc"}], [[6.0, -2.0], [6.0, 11.0], {"subtype": "segment", "stroke": "#ccc"}], [[7.0, -2.0], [7.0, 11.0], {"subtype": "segment", "stroke": "#ccc"}], [[-1.1713032141645456, 4.937042571331637], [-0.2342606428329086, 6.108345785496182], {"subtype": "segment"}], [[-0.2342606428329086, 6.108345785496182], [2.108345785496182, 4.234260642832909], {"subtype": "segment"}], [[2.108345785496182, 4.234260642832909], [1.1713032141645456, 3.062957428668364], {"subtype": "segment"}], [[-5.0, 8.960468635614927], [-0.7027819284987271, 5.522694178413909], {"subtype": "segment"}], [[-5.0, 8.0], [-5.0, 10.0], {"subtype": "segment"}], [[5.0, 0.0], [-5.0, 8.0], {"subtype": "segment"}], [[-5.0, 0.0], [5.0, 0.0], {"subtype": "segment"}]], "arc": [[[5.0, 0.0], [1.5, 1.5], 141.3401917459099, 180.0, false, {}]], "circle": [[[0.4685212856658182, 4.585651607082273], 0.1, {"fill": "black"}]], "label": [[[3.0, -0.5], "\\alpha", "above", {}], [[-0.03147871433418181, 4.085651607082273], "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": [[-5.0, 5.0], [-8.0, 6.0]], "scale": [40, 40]}, "line": [[[-4.0, -7.0], [4.0, -7.0], {"subtype": "segment", "stroke": "#ccc"}], [[-4.0, -6.0], [4.0, -6.0], {"subtype": "segment", "stroke": "#ccc"}], [[-4.0, -5.0], [4.0, -5.0], {"subtype": "segment", "stroke": "#ccc"}], [[-4.0, -4.0], [4.0, -4.0], {"subtype": "segment", "stroke": "#ccc"}], [[-4.0, -3.0], [4.0, -3.0], {"subtype": "segment", "stroke": "#ccc"}], [[-4.0, -2.0], [4.0, -2.0], {"subtype": "segment", "stroke": "#ccc"}], [[-4.0, -1.0], [4.0, -1.0], {"subtype": "segment", "stroke": "#ccc"}], [[-4.0, 0.0], [4.0, 0.0], {"subtype": "segment", "stroke": "#ccc"}], [[-4.0, 1.0], [4.0, 1.0], {"subtype": "segment", "stroke": "#ccc"}], [[-4.0, 2.0], [4.0, 2.0], {"subtype": "segment", "stroke": "#ccc"}], [[-4.0, 3.0], [4.0, 3.0], {"subtype": "segment", "stroke": "#ccc"}], [[-4.0, 4.0], [4.0, 4.0], {"subtype": "segment", "stroke": "#ccc"}], [[-4.0, 5.0], [4.0, 5.0], {"subtype": "segment", "stroke": "#ccc"}], [[-4.0, -7.0], [-4.0, 5.0], {"subtype": "segment", "stroke": "#ccc"}], [[-3.0, -7.0], [-3.0, 5.0], {"subtype": "segment", "stroke": "#ccc"}], [[-2.0, -7.0], [-2.0, 5.0], {"subtype": "segment", "stroke": "#ccc"}], [[-1.0, -7.0], [-1.0, 5.0], {"subtype": "segment", "stroke": "#ccc"}], [[0.0, -7.0], [0.0, 5.0], {"subtype": "segment", "stroke": "#ccc"}], [[1.0, -7.0], [1.0, 5.0], {"subtype": "segment", "stroke": "#ccc"}], [[2.0, -7.0], [2.0, 5.0], {"subtype": "segment", "stroke": "#ccc"}], [[3.0, -7.0], [3.0, 5.0], {"subtype": "segment", "stroke": "#ccc"}], [[4.0, -7.0], [4.0, 5.0], {"subtype": "segment", "stroke": "#ccc"}], [[0.0, 0.0], [2.4390243902439024, 3.048780487804877], {"subtype": "segment", "arrow-end": "classic-wide-long"}], [[0.0, 0.0], [-2.4390243902439024, 1.951219512195122], {"subtype": "segment", "arrow-end": "classic-wide-long"}], [[0.0, 0.0], [0.0, -5.0], {"subtype": "segment", "arrow-end": "classic-wide-long"}]], "circle": [[[0.0, 0.0], 0.1, {"fill": "black"}]], "label": [[[0.0, 0.0], "G", "above", {}], [[1.6880334807877693, 1.149573215369784], null], [[-1.5943292236546058, 0.5070884704317427], null], [[0.6, -2.5], null], [[1.0, -3.5], "\\overrightarrow{\\rm P}", "above", {}], [[4.219512195121951, 0.5243902439024386], "\\overrightarrow{\\rm R}", "above", {}], [[-0.7195121951219512, 0.975609756097561], "\\overrightarrow{\\rm T}", "above", {}]]}
Données
- - Accélération de la pesanteur : \( g = 9,81\:\text{m}\mathord{\cdot}\text{s}^{-2} \)
- - Masse du solide : \( m = 102\:\text{g} \)
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.