Jogku is a Korean sport similar to football and volleyball.
2 teams face each other and the objective is to return the ball to the opponent, using their feet or shin.
Newton's first law of motion (inertia) states that when an object is at rest it stays at rest and when an object is in motion stays in motion.
In Jogku the player that is hitting the ball is using the first law of motion. He is hitting the ball with force to get over the other side. If no force is applied, the ball doesn't go anywhere.