οριακή ταχύτητα

Felix Baumgartner made history and conquered the skies

by becoming the first person to break the sound barrier without vehicular power.

Skydiving from a balloon a historic 39,068 meters above Earth's surface,

he plummeted down, reaching estimated speeds of 1,360 kilometers per hour.

Air drag is a resistive force that slows anything

moving in the Earth's atmosphere.

When Felix is free falling, the force of gravity

is constant and points downward toward the center of the Earth.

Immediately upon jumping, this is the only force acting on him.

At lower velocities, the effects of air drag can be ignored.

But during high speed phenomena, air drag must be included.

Air drag always opposes the direction of motion.

While the force of gravity is constant, air drag

rapidly increases with velocity.

If the velocity gets large enough, the force of air drag

will equal the force of gravity and cancel each other out.

With no acceleration, Felix's velocity will remain constant from this point

until his parachute opens.

This is terminal velocity.

Without understanding the fundamental physics behind the fall,

Felix could easily have made mistakes and not survived the jump.

Understanding the laws of physics make seemingly impossible feats achievable.