Inertia of motion :


A body in a state of notion, continues to be in the state of motion with the same  speed in the same direction in a straight line unless an external force is applied on it to change its state this property of body is called the inertia of motion.


1-An athlete often runs before taking a long jump, why ?


Ans-The reason is that by running he brings his entire body in the state of motion. When the body is in motion. It becomes easier to take a long jump.


Related question


1-A cyclic riding along a level road does not come to rest immediately after he stops pedalling, why?


2-When a passenger jumps out of a moving train, he falls down, why?


3-When a running car stops suddenly, the  passenger tends to lean forward, why?


4-A ball thrown vertically upwards by a person in a moving train comes back to his hand, why ?


here is the link you can see the Answer-

https://knowledgecraker.blogspot.com/2020/06/what-is-inertia-and-their-types-related.html