Football match is one of the sports that many people like. I don't know if you have ever thought about enjoying the game with your body besides cheering for your favorite teams and stars and reveling in every 1 goal? In fact, this sport contains a lot of physical knowledge. Now we can see from several common phenomena on the football field that 1: 1 the ball rolls slower and slower. The ball kicked on the court rolled slower and slower and finally stopped. This is because the kicked football keeps its original motion state due to inertia and continues to roll along the original motion direction; In the direction of motion, it is only affected by rolling friction, which changes the motion state of football, hinders the rolling of football, makes the ball roll slower and slower, and finally stops moving. After the ball falls, the height of each rise is lower than the previous 1 time. It can be analyzed from the viewpoint of energy: when the ball falls, it will lose 1 part of mechanical energy because it overcomes the friction between the ball and the air; At the same time, the ball will lose 1 part of its mechanical energy when it hits the ground, so the mechanical energy of the ball will gradually decrease, so the height of the ball will become smaller and smaller. 1 23 1 Page 3 The goalkeeper catches the ball. When a player shoots with big feet, the ball speed can be as high as 100 km/h, and if the goalkeeper stops the ball with his chest, the impact on his chest will be as high as1500 n; If you catch the ball by hand, the impulse should be reduced to 500 N, because the braking distance of the ball can be extended by three times through the movement of the arm. The goalkeeper took a penalty. When the goalkeeper takes a penalty, the success rate of 1 is only related to the goalkeeper's judgment and reaction ability. Why? Because the penalty spot is only 9.15m away from the goal and the speed of the ball can be as high as 100 km/h when shooting, the time for the ball to reach the goal is about 0.32 seconds, and the reflection time of the human brain is about 0.6 seconds, so the time for the football to reach the goal will be much shorter than the reflection time of the human brain, so the goalkeeper has no time to adjust his consciousness, so whether the penalty spot can be saved is directly related to the goalkeeper's prediction of the goal direction. It is for this reason that when we watch the penalty shootout, it is not surprising that the ball obviously flies to the left of the goal and the goalkeeper jumps to the right. The athlete leaned forward when he tripped. When a fast runner trips his opponent's foot or body, he will fall forward. The reason for this is that the lower body stopped moving because it was caught, but the upper body kept moving forward because of inertia, so the runner fell forward when he tripped. 6 spray therapy. In football matches, it is often seen that athletes roll on the ground with their legs in their arms after colliding with each other and falling down. At this time, the team doctor will quickly enter the field, take out the 1 bottle from the medicine box and spray 1 white mist on the player's pain. 1 minute later, the pain of the wounded will disappear and they can re-enter the game. In fact, this is because the bottle is filled with "cold air mist analgesia", which is composed of CFC and 1 analgesic and wound-treating drugs. When this liquid medicine is sprayed on the wound from the nozzle, it quickly evaporates into a mist. Because vaporization absorbs a lot of heat, the temperature of the injured part of the athlete will drop sharply, the blood vessels will contract, the nerve will be paralyzed, and the pain will soon disappear.

The formation of curved ball. When we watch the ball, we often hear the commentator say that the ball draws a beautiful arc in the air and hangs directly in the corner of the goal. Then why does the ball make a beautiful arc in the air? That's because when a player kicks a ball, he rubs the ball with the inside or outside of his foot to make the ball move horizontally in the air, which leads to the air speed on both sides of the ball being different from 1. According to the relationship between air velocity and pressure, the force of air on the ball in the horizontal direction is different from 1, so the ball bends in the horizontal direction perpendicular to the ball's forward direction while moving forward, thus forming a "beautiful arc".