Playing football elasticity is there a yellow card warning

What are the rules for playing football? What needs attention
I am a layman in football. I don't know what rules to pay attention to when playing football? Under what circumstances is a foul? Is there a yellow cardIsn't football elastic enough in a real game
The ball used in the game is usually full of Qi, which is much harder than playing football. Theoretically, the elasticity is worse, but the inertia is very sufficient. For example, the falling speed of the high ball is faster, and whether it will be higher after bouncing depends on the situationExcuse me, what are all the essentials of playing football
When the ball falls to the ground from a height of 2 meters, the height of the first rebound shall not be more than 65 cm, nor less than 50 cm. The ball used in the matches hosted by the International Football Federation and under the jurisdiction of the football leagues of all continents must bear one of the following three symbols: &\x2027; The official "FIFA approved" markAfter the football is kicked out, it always receives the elasticity of the foot to make the football move forward, right
When the ball leaves the foot, it will not be subject to the force of the foot, but will move forward due to the inertia. At this time, it will be subject to the resistance of gravity and wind, so the trajectory is generally curveWhat force do people exert when playing football
Muscle strength is also available. After eating all day and exercising, your muscles will be strong under your exercise. Athletes are not vegetarianThe ball deforms to produce elasticity at the moment of kicking
B. When a football is flying in the air, it will be affected by gravity and air resistance. The direction and speed of the football will change, that is, the motion state will change; Therefore, the statement of B is correct; C. When the foot kicks the ball, the ball deforms elastically, resulting in elasticity; So C is correct; D. A football flying in the airWhen playing football, does the ball get elasticity
I think this thing still depends on myself, just for a moment, so don't worry too much
The theorem of kinetic energy in playing football is elasticity neglected in doing work
Of course, for example, a 200N kicking ball can achieve a speed of 5m per second and then roll for 10m. This is the kinetic energy theorem. The work done by people on the ball is equal to the kinetic energy increment of the ball. However, at this time, the ball only receives gravity, support and frictionIs there any relation between playing football and elasticity
Also, the bouncing header is more powerful. Football is a comprehensive sport, and every attribute is very importantWhen a foot kicks a football, why is the ball only affected by gravity when it leaves the foot? What about the force of the foot on the ball
The force of the foot on the ball is elastic and returns to zero at the moment of departure. If the air resistance is ignored, it is only affected by gravity