If a person accelerates from rest in a 100 m sprint, maximum speed is reached at about the 30–40 m mark. The speed does not increase linearly with time. I found that a person can reach about 75% of maximum speed after the first 5 m. If a person then jumps forward after reaching the 5 m mark, the forward jump speed is typically about 0.5 m/s less that the corresponding run speed at the 5 m mark, because the action of planting the front jumping foot increases the backward friction force acting on the front foot. If a person dives head first at the 5 m mark, there is an additional loss of about 0.4 m/s in the forward speed due to the braking force required to generate the necessary forward rotation.