Frictional force: This force is the force that acts parallel to the runner in the opposite direction. It depends on how the
track and the runner's foot interact and the normal force (force acting perpendicular to the surface which the ground exerts)
As sprinting has developed over the years, runners have learned how to use some of these forces to their advantage. One
of them being the force of GRAVITY.
The force of gravity is the force exerted between two masses of different sizes. The smaller mass is attracted to the
larger. In our case the world is the large mass, and we are the smaller masses. The force of gravity pulls us towards the
earth and that's why we do not float off into outerspace.
Runners can use gravity do their advantage. In order to use gravity to work with them, runners lean forward. Leaning allows
gravity to pull the runner forward, and it makes the work done by the legs easier. If the runner developes the proper lean(from
the ankles, not the waist) he or she will be able to run easier and faster. The force of gravity will allow this.
|this shows the lean a runner must have run easier