Place it at the centre of a fail sequence, after the setup and before the reaction shot, then follow the fall with SpongeBob Fail for the payoff and add Classic Punch on the impact frame to sharpen the hit.
About this sound
This six-second cartoon effect runs through a full gag in one take: a fast whoosh as the boomerang leaves, a firm comic thump on impact, then a wobbling, sinking spin as it drops away. It feels mischievous and silly, turning a knockdown into a joke instead of a hurt. The style comes from golden-age American animation, where exaggerated Foley carried the punchline.