Inertia- an object in motion will stay in motion in the same direction, and an object at rest will stay at rest until acted on by an unbalanced force The balls outside the field are staying still, and will remain still until someone kicks the ball. The ball on the field continues to travel until friction acts enough on the ball to cause it to stop.
F=ma- Force is equal to mass multiplied by acceleration The soccer player kicks the small soccer ball causing it to accelerate, and due to the small mass of the soccer ball, it travels much faster with a force that does not need to be very great. Notice how the player kicking the ball with more mass with the same force causes it to move slower and not travel as far.
Action and Reaction- any action is met by an equal and opposite reaction The ball falls against the ground and pushes against the ground, but the ground has a great mass, so the ground does not shift very much, if at all. However, the ground pushes back with equal force, and since the ball has less mass, it bounces