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the match if it absorbs dirt and moisture.) The ball’s inflatable bladder, lining, leather cover, and stitching all affect its weight. Newton’s Laws and Soccer Newton’s law of inertia states that an object at rest will remain at rest unless an unbalanced force (in this case, the kicker) acts on it. Therefore, the F=ma equation applies in this case, and the force of the kick is the major force acting on the ball. The value of m is the mass of the soccer ball, and F is the amount of force the kicking or throwing player uses. Acceleration ( a ) is produced when a force acts on a mass. It is now easy to see why FIFA wants to control the mass of the ball, right? Eventually, of course, the

soccer ball does stop, hopefully in the goal. Newton’s law of motion comes into play here: An object in motion continues in motion with the same speed and in the same direction unless acted on by an unbalanced force. Gravity, drag, and friction are also forces that act on the soccer ball. Gravity pulls

the ball down toward the ground as the ball is in flight. Friction is the force that acts on the ball as it moves over the playing surface, such as grass or a hard artificial surface. Friction occurs as two surfaces (the ball and the field) make contact with each other. As the soccer ball rubs against the ground, a resistance in movement occurs to help slow the ball down. Drag is the force of the air pushing on the ball as it travels in flight. Think of drag as air friction. The air around the ball helps slow it down.

10 CONNECTING STEM AND SPORTS | SOCCER