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public class mass extends Mover
{
    /**
     * Act - do whatever the mass wants to do. This method is called whenever
     * the 'Act' or 'Run' button gets pressed in the environment.
     */
    public mass()
    {
        vector v1 = new vector();
        v1.setLength(3);
        v1.setAngle(Math.PI/60);
    }

    public void act() 
    {
        setLocation(getX()+v1.getDx(), getY()+v1.getDy());
    } 
}