Question

Why does an athlete run for a distance before taking a jump?

Answer 1

An athlete runs before jumping to gain momentum. Because it helps in jumping higher and longer because of inertia of motion gained due to the motion.
When the athletes Jump they already have a forward motion that would be greater than that of a jump made from standing in one spot.
Note: The Law of inertia i.e., Newton’s First Law of Motion supports the above explanation.