重力场中，两弹性系数为k的弹簧中间架起一质量为M的托盘，盘静止。托盘质心上h处有一质量为m、半径为r的小球，速度为v（可正可负）。用数值模拟的方法模拟托盘及球的运动-Gravitational field, the two elastic spring coefficient k, the middle set up a mass M of the tray, plate stationary. H at the heart of quality tray has a mass m, radius r of the ball, speed of v (can be positive or negative). Numerical simulation method to simulate the movement of the tray and ball