private void Update()
 {
     if (ball != null)
     {
         if ((Vector3.Dot(gameObject.transform.up, Vector3.up) < MinAngle && Vector3.Dot(gameObject.transform.up, Vector3.up) > -MinAngle) && !knockedOver)
         {
             ball.ChangeScore(1);
             knockedOver = true;
         }
     }
 }