Black Friday: lifetime access is on a special offer in the app, until November 30. Black Friday: special offer on lifetime access, until November 30. Download
충격력은 물체가 충돌할 때 발생하는 힘입니다.chung-gyeoknyeogeun mulchega chungdolhal ttae balseonghaneun himimnida.The impact force is the force generated when an object collides.