Move body LibGDX Box2D

Hello I have a body and I want to move it. When I press the mouse button my body should move at that position (on the const speed)on the screen. I have override two methods(x1, y1 – point where my body need to go)

    public boolean touchDown(int x1, int y1, int pointer,
            int button) {
        x = x1;
        y = y1;
        move.set(x1 - ball.getPosition().x, y1 - ball.getPosition().y).nor();
        return false;
    }

    @Override
    public boolean touchUp(int screenX, int screenY, int pointer,
            int button) {
        move.set(ball.getPosition().x, ball.getPosition().y);
        return false;
    }

and in my rener method I have write this

ball.applyForceToCenter(move, true);

but my ball don’t move! why? whats wrong? is there are any alternatives how to move mody at specific point on the screen?