Final answer:
A team can change its goalkeeper before a penalty shot and the original goalkeeper can return to the field thereafter, following proper procedures. A soccer ball can theoretically be kicked 95 m without touching the ground at a speed of 30 m/s, and the displacement over time graph of the ball would look similar to that of a hockey puck. Protective equipment such as shin guards and a protective cup are important for player safety.
Step-by-step explanation:
A team is allowed to change its goalkeeper before defending against a penalty shot, but this is typically governed by the rules of the specific football association. Once the penalty shot is taken, teams can usually substitute players, including the goalkeeper, assuming they have not used up their allowed substitutions and follow the proper procedure. After a penalty has been taken, provided it is in accordance with the rules, the original goalkeeper may be allowed to re-enter the field of play.
In terms of physical feasibility, a goalkeeper could theoretically kick a soccer ball 95 m without it touching the ground if given a speed of 30 m/s, but factors like air resistance and ball trajectory would create practical challenges, making it a rare occurrence in actual play.
To visualize the displacement over time of a ball kicked back to the goalie and then returned, without knowing the time, the displacement-time graph would indeed look similar to that of a hockey puck moving back and forth on ice, assuming no external forces other than the initial kick and the stop by the goalie. It would show displacement increasing with time, then becoming constant once the ball stops, and then reversing direction as the goalie sends the ball back.
Protective equipment in soccer is crucial for safety. Along with shin guards, a protective cup is recommended to protect against groin injuries which can occur from a kicked ball or direct contact during the game.