Gravitational Potential Energy

How do swimmers use Physics to get the most out of their starts?

The true power of the PowerStartsTM TechniqueTM comes from converting entry speed (the speed of entry into the water) into thrust (a force pushing the swimmer forward into his surge and breakout.  The higher the entry speed, the more thrust can be generated.  Higher entry speeds are generated by higher potential energy at the peak of the start dive.

In other words, the higher you jump, the faster you fall, the greater your entry speed, the stronger the thrust.

Physics Principles

Potential energy -- is the energy of an object due to its position or state.

Velocity -- is how quickly an object changes its position. The higher the velocity the quicker an object travels between two locations. "Phrases like, ' fast..., how quickly,' are used to describe velocity."  Often the word "speed" is incorrectly substituted for the word "velocity" in usage. But "velocity" is actually a vector, speed with direction.

Acceleration -- describes how quickly an object changes its velocity. "Phrases like, '...slow down..., ...speed up..., ...change speed... and ...change velocity...' are used to describe acceleration."

Newton's Third Law -- explains why forces act in pairs:  "For every action, there is and equal and opposite reaction."

Why the toes should hang over the front of the starting platform.

 Another PowerStartsTM Secret 

The body uses kinetic energy to energize the vertical jump.  This energy is first generated in the movements of the upper body as the head and arms are raised and should also be generated in the lower body as a squatting motion begins while the arms are rapidly rising to the streamline position.

At the same time that the arms are rising and the squatting of the legs movement is occurring, the center of gravity should be coming forward over the front of the feet as the heels lift-up off the platform.  At the lowest point of the squat position, the body should snap-up with the arms leading the way as though the energy generated from the stretched muscles in the legs is going to be shot out of the fingers up towards the goal of the backstroke flags.

Then as the legs are extended and the body has launched-up-and-out, a final energy-blast should come from the toes which are wrapped over the end of the platform. The toes don't have a lot of strength but they add to the projectile guidance by extending the distance of the trajectory.