MC Java Edition Knockback

Hi guys, Im trying to create knockback like in mc java, but i dont get it working. I tried something like this:

PHP:

$vec = $damager->getDirectionVector();
                            $entity->setMotion($vec->setComponents($vec->x + 0.5, 0.4, $vec->y + 0.5));

but it wasnt smooth

In MC Java, the players are knocked more back and not so high like in mcpe.

Can you guys pls help me?