Speed is Newtonian. That is, it follows Newton's third law of motion; for every action there is an equal and opposite reaction. Speed is the result of of ground contact force (GCF) and ground contact time (GCT). How these two forces work together is the new formula for speed.
When one body exerts a force on a second body, the second body simultaneously exerts a force equal in magnitude and opposite in direction to that of the first body. -Newton's Third Law of Motion
The amount of force a sprinter puts into the ground has a direct effect on speed. A study at Harvard University published in 2000 found that the fastest runners generated almost 1.26 times more GCF than the slowest runners. This result seems consistent with the idea that speed is Newtonian.
The same study also found that the slowest runners spend almost twice as much time on the ground as the fastest runners. Slower runners had longer GCT.
The amount of time spent applying this force also has a direct effect on speed. A study published in 1986 looked at the ground contact times of jogging, running and sprinting. This study found the GCT for jogging to be .26 seconds, running .20 seconds, and sprinting .14 seconds.
Shorter ground contact times coupled with greater ground contact forces generated faster speed. So, the new formula for speed is: SPEED= GCF / GCT.