Answer-An Athlets runs before long jump to get advantage on –

An athlete does so to build up forward momentum so that when he jumps he already has a forward motion that would be greater than that of a jump made from standing in one spot. He needs forward momentum to get a good long jump and the best way is to have a running start. In this way, he gets advantage in terms of inertia of motion which is the tendency of an object to resist a change in motion.