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": [[-6.0, 6.0], [-3.0, 10.0]], "scale": [20, 20]}, "line": [[[-5.0, -2.0], [5.0, -2.0], {"subtype": "segment", "stroke": "#ccc"}], [[-5.0, -1.0], [5.0, -1.0], {"subtype": "segment", "stroke": "#ccc"}], [[-5.0, 0.0], [5.0, 0.0], {"subtype": "segment", "stroke": "#ccc"}], [[-5.0, 1.0], [5.0, 1.0], {"subtype": "segment", "stroke": "#ccc"}], [[-5.0, 2.0], [5.0, 2.0], {"subtype": "segment", "stroke": "#ccc"}], [[-5.0, 3.0], [5.0, 3.0], {"subtype": "segment", "stroke": "#ccc"}], [[-5.0, 4.0], [5.0, 4.0], {"subtype": "segment", "stroke": "#ccc"}], [[-5.0, 5.0], [5.0, 5.0], {"subtype": "segment", "stroke": "#ccc"}], [[-5.0, 6.0], [5.0, 6.0], {"subtype": "segment", "stroke": "#ccc"}], [[-5.0, 7.0], [5.0, 7.0], {"subtype": "segment", "stroke": "#ccc"}], [[-5.0, 8.0], [5.0, 8.0], {"subtype": "segment", "stroke": "#ccc"}], [[-5.0, 9.0], [5.0, 9.0], {"subtype": "segment", "stroke": "#ccc"}], [[-5.0, -2.0], [-5.0, 9.0], {"subtype": "segment", "stroke": "#ccc"}], [[-4.0, -2.0], [-4.0, 9.0], {"subtype": "segment", "stroke": "#ccc"}], [[-3.0, -2.0], [-3.0, 9.0], {"subtype": "segment", "stroke": "#ccc"}], [[-2.0, -2.0], [-2.0, 9.0], {"subtype": "segment", "stroke": "#ccc"}], [[-1.0, -2.0], [-1.0, 9.0], {"subtype": "segment", "stroke": "#ccc"}], [[0.0, -2.0], [0.0, 9.0], {"subtype": "segment", "stroke": "#ccc"}], [[1.0, -2.0], [1.0, 9.0], {"subtype": "segment", "stroke": "#ccc"}], [[2.0, -2.0], [2.0, 9.0], {"subtype": "segment", "stroke": "#ccc"}], [[3.0, -2.0], [3.0, 9.0], {"subtype": "segment", "stroke": "#ccc"}], [[4.0, -2.0], [4.0, 9.0], {"subtype": "segment", "stroke": "#ccc"}], [[5.0, -2.0], [5.0, 9.0], {"subtype": "segment", "stroke": "#ccc"}], [[-1.0606601717798214, 4.060660171779821], [1.1102230246251565e-16, 5.121320343559643], {"subtype": "segment"}], [[1.1102230246251565e-16, 5.121320343559643], [2.1213203435596424, 3.0], {"subtype": "segment"}], [[2.1213203435596424, 3.0], [1.0606601717798214, 1.9393398282201786], {"subtype": "segment"}], [[-3.0, 7.060660171779821], [-0.5303300858899107, 4.590990257669732], {"subtype": "segment"}], [[-3.0, 6.0], [-3.0, 8.0], {"subtype": "segment"}], [[3.0, 0.0], [-3.0, 6.0], {"subtype": "segment"}], [[-3.0, 0.0], [3.0, 0.0], {"subtype": "segment"}]], "arc": [[[3.0, 0.0], [1.5, 1.5], 135.0, 180.0, false, {}]], "circle": [[[0.5303300858899106, 3.5303300858899105], 0.1, {"fill": "black"}]], "label": [[[1.0, -0.5], "\\alpha", "above", {}], [[0.030330085889910596, 3.0303300858899105], "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": [[-6.0, 6.0], [-10.0, 6.0]], "scale": [40, 40]}, "line": [[[-5.0, -9.0], [5.0, -9.0], {"subtype": "segment", "stroke": "#ccc"}], [[-5.0, -8.0], [5.0, -8.0], {"subtype": "segment", "stroke": "#ccc"}], [[-5.0, -7.0], [5.0, -7.0], {"subtype": "segment", "stroke": "#ccc"}], [[-5.0, -6.0], [5.0, -6.0], {"subtype": "segment", "stroke": "#ccc"}], [[-5.0, -5.0], [5.0, -5.0], {"subtype": "segment", "stroke": "#ccc"}], [[-5.0, -4.0], [5.0, -4.0], {"subtype": "segment", "stroke": "#ccc"}], [[-5.0, -3.0], [5.0, -3.0], {"subtype": "segment", "stroke": "#ccc"}], [[-5.0, -2.0], [5.0, -2.0], {"subtype": "segment", "stroke": "#ccc"}], [[-5.0, -1.0], [5.0, -1.0], {"subtype": "segment", "stroke": "#ccc"}], [[-5.0, 0.0], [5.0, 0.0], {"subtype": "segment", "stroke": "#ccc"}], [[-5.0, 1.0], [5.0, 1.0], {"subtype": "segment", "stroke": "#ccc"}], [[-5.0, 2.0], [5.0, 2.0], {"subtype": "segment", "stroke": "#ccc"}], [[-5.0, 3.0], [5.0, 3.0], {"subtype": "segment", "stroke": "#ccc"}], [[-5.0, 4.0], [5.0, 4.0], {"subtype": "segment", "stroke": "#ccc"}], [[-5.0, 5.0], [5.0, 5.0], {"subtype": "segment", "stroke": "#ccc"}], [[-5.0, -9.0], [-5.0, 5.0], {"subtype": "segment", "stroke": "#ccc"}], [[-4.0, -9.0], [-4.0, 5.0], {"subtype": "segment", "stroke": "#ccc"}], [[-3.0, -9.0], [-3.0, 5.0], {"subtype": "segment", "stroke": "#ccc"}], [[-2.0, -9.0], [-2.0, 5.0], {"subtype": "segment", "stroke": "#ccc"}], [[-1.0, -9.0], [-1.0, 5.0], {"subtype": "segment", "stroke": "#ccc"}], [[0.0, -9.0], [0.0, 5.0], {"subtype": "segment", "stroke": "#ccc"}], [[1.0, -9.0], [1.0, 5.0], {"subtype": "segment", "stroke": "#ccc"}], [[2.0, -9.0], [2.0, 5.0], {"subtype": "segment", "stroke": "#ccc"}], [[3.0, -9.0], [3.0, 5.0], {"subtype": "segment", "stroke": "#ccc"}], [[4.0, -9.0], [4.0, 5.0], {"subtype": "segment", "stroke": "#ccc"}], [[5.0, -9.0], [5.0, 5.0], {"subtype": "segment", "stroke": "#ccc"}], [[0.0, 0.0], [3.4999999999999996, 3.500000000000001], {"subtype": "segment", "arrow-end": "classic-wide-long"}], [[0.0, 0.0], [-3.4999999999999996, 3.499999999999999], {"subtype": "segment", "arrow-end": "classic-wide-long"}], [[0.0, 0.0], [0.0, -7.0], {"subtype": "segment", "arrow-end": "classic-wide-long"}]], "circle": [[[0.0, 0.0], 0.1, {"fill": "black"}]], "label": [[[0.0, 0.0], "G", "above", {}], [[2.1742640687119286, 1.3257359312880719], null], [[-2.174264068711928, 1.325735931288071], null], [[0.6, -3.5], null], [[1.0, -4.5], "\\overrightarrow{\\rm P}", "above", {}], [[4.75, 0.7500000000000004], "\\overrightarrow{\\rm R}", "above", {}], [[-1.2499999999999998, 1.7499999999999996], "\\overrightarrow{\\rm T}", "above", {}]]}
Données
- - Accélération de la pesanteur : \( g = 9,81\:\text{m}\mathord{\cdot}\text{s}^{-2} \)
- - Masse du solide : \( m = 214\:\text{g} \)
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.