Hai tàu A và B ban đầu cách nhau một khoảng l Chúng ch
A.\(a.\,\,\sin \beta = \dfrac{{{v_1}}}{{{v_2}}}\sin \alpha ;\,\,t = \dfrac{l}{{{v_1}\cos \alpha + {v_2}\cos \beta }};\,\,b.\,\,\dfrac{{{v_2}}}{{{v_1}}} = \sin \alpha \).
B.\(a.\,\,\sin \beta = \dfrac{{{v_1}}}{{{v_2}}}\sin \alpha ;\,\,t = \dfrac{l}{{{v_1}\cos \alpha + {v_2}\cos \beta }};\,\,b.\,\,\dfrac{{{v_2}}}{{{v_1}}} = \cos \alpha \).
C.\(a.\,\,\sin \beta = \dfrac{{{v_1}}}{{{v_2}}}\sin \alpha ;\,\,t = \dfrac{l}{{{v_1}\cos \alpha + {v_2}\cos \beta }};\,\,b.\,\,\dfrac{{{v_2}}}{{{v_1}}} = \tan \alpha \).
D.\(a.\,\,\sin \beta = \dfrac{{{v_1}}}{{{v_2}}}\sin \alpha ;\,\,t = \dfrac{l}{{{v_1}\cos \alpha + {v_2}\cos \beta }};\,\,b.\,\,\dfrac{{{v_2}}}{{{v_1}}} = \cot \alpha \).