java - 物体下落时如何施加重力？

Question

我有一个物体(是一个球)，其位置位于屏幕顶部，每当我开始运行程序时，它就会直接落下。问题是球以恒定速度下落，我希望它在重力作用下加速下落，当它到达地面时，我希望它在停止移动之前再弹跳几次。有人可以帮我解决这个问题吗？

这是我尝试过的:

public class Balls
{
private double x;
private double y;
private double speed;
private double mass;
private final double gravity = -9.8;
private final double width = 100;
private double height = 100;
private final Board board;
private boolean isFalling = false;
private double distance_y;
private double distance_x = 0;

public Balls(double x, double y, double speed, double mass, Board board)
{
    this.x = x;
    this.y = y;
    this.board = board;
    this.speed = convertToMeterSpeed(speed);
    this.mass = mass;

}

private double convertToMeterSpeed(double speed)
{
    return speed / 3.6;
}

public void moveBall(long dt)
{

    double time = dt / 1e9; // seconds
    double diameter_y = height / 2.0;
    double radius = (diameter_y / 2.0);
    double velocity_y = speed * dt / 1e9;
    distance_y = board.getHeight() - y;

    if (distance_y - radius > 0)
    {
        isFalling = true;
    }

    if (isFalling)
    {
        if (distance_y >= height)
        {
            distance_y = distance_y + (0.5 * gravity * (time * time));  // represents the 1/2,
            distance_y = board.getHeight() - height;
            y += velocity_y;
        }

        else
        {
            isFalling = false;
        }

        try
        {
            Thread.sleep(10);
        }
        catch (InterruptedException e)
        {

        }
    }
}


public void render(Graphics2D g2d)
{
         g2d.fillOval((int) x, (int) y, (int) width, (int) height);

}
}

Answer 1

速度 = v0 + gt^2/2，

哪里

v0 - 初始速度

地球上的 g = 9.81。

t - 时间

现在您可以随时计算速度。