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圆锥曲线是解析几何的重点,圆锥曲线运动在物理世界中广泛存在.如平抛物体的运动轨迹是抛物线,星体的运动轨道有的是圆,有的是椭圆,有的是抛物线,有的是双曲线. 物理教材中,用描点法得到物体作平抛运动的轨迹:如图所示建立了一直角坐标系,设运动物体的坐标为(x,y),则x=v0t①y=1/2gt2②由①整理出t=x/v0代入②,得x2=(2v02/g)y(x≥0). 这即是抛物线的标准方程,所以平抛物体的运动轨迹是抛物线.
Conic curve is the focus of analytical geometry. Cone curve motion exists widely in the physical world. For example, the motion path of a plane paraboloid is a parabola. Some of the orbits of astral are circular, some are elliptical, some are parabola, and some are hyperbolic. In physics textbooks, The dot-dot method obtains the trajectory of the object as the plane-throwing motion: as shown in the figure, a straight angle coordinate system is established. Let the coordinate of the moving object be (x, y), then x = v0t1y = 1/2gt22 is sorted out by 1 and t = x/ Substituting v0 into 2 results in x2=(2v02/g)y(x≥0). This is the standard equation of the parabola, so the trajectory of the parabolic object is a parabola.