@Override
public boolean fling(float velocityX, float velocityY, int button) {


  ball.getBody().setActive(true);
  System.out.println("Mouse pos is " + mouse.toString());
  ball.getBody().applyForce(new Vector2(mouse.x - ball.getBody().getPosition().x, 30), ball.getBody().getWorldCenter(), true);


  return super.fling(velocityX, velocityY, button);
}

So, how exaclty could i achive something like in that picture above? Any tips would be greatly appreciated!

@Override
public boolean fling(float velocityX, float velocityY, int button) {
  // Unprojecting the mouse coordinates here (screen into world coordinates).
  unproject(mouse);
  ball.getBody().setActive(true);
  System.out.println("Mouse pos is " + mouse.toString());
  // Forgot about the * PPM there.
  ball.getBody().applyForce (
     new Vector2(mouse.x - (ball.getBody().getPosition().x * PPM), 25),
     ball.getBody().getWorldCenter(),
     true
 );
 return super.fling(velocityX, velocityY, button);
}

So, right now, the results are slightly better, meaning that the body somewhat moves accordingly to the mouse position. Yet, the "mouse.x - ball center" value isn't for sure the right choice here; i'd like to make it so it would only be possible to start flinging if the mouse is dragging the body itself, something like this:

@Override
public boolean fling(float velocityX, float velocityY, int button) {
  unproject(mouse);
  // Something like this...
  if (ball.contains(mouse)) {
  ...
  ...
  ...
  }
  return super.fling(velocityX, velocityY, button);
}

where, my contains method looks like this:

public boolean contains(Vector2 worldCoordinates) {
  return getBounds().contains(worldCoordinates);
}

@Override
public Rectangle getBounds() {
  return new Rectangle(
  body.getPosition().x * PlayState.PPM - size.x / 2,
  body.getPosition().y * PlayState.PPM - size.y / 2,
  size.x,
  size.y
  ); 
}