Since I am a ballet dancer, it would be fair to mention one of the most impressive ballet moves performed: the grand jete. For non-dancers, this move can be described as a "split like jump"; the dancer takes off by extending one leg into the air and taking off into a projectile type motion. In the best case scenario, the ballerina hits a perfect split at the peak of her parabolic path, creating a split second mesmerizing image for the audience to enjoy. In order to complete this leap, several physics ideas must be thought of and considered carefully. First off would be the gathering of energy. It is impossible, no matter how strong your legs are or how much experience you have, to perform a grand jete from a static position. A dancer usually performs a series of quick moving steps across the floor in order to gain the momentum and more importantly, kinetic energy. Hence, when the dancer extends his or her leg at an angle to the horizontal stage (creating projectile motion) this gathered kinetic energy is transferred into potential energy, allowing the dancer to follow a parabolic path. What allows the dancer to hit a peak of their motion in a split and to appear almost frozen in mid air would be the lack of gravitational acceleration downward. For a split second, at the top of the dancer's path, their upward vertical acceleration has been reduced to zero and they are yet to experience a gravitational force downward. Finally, it is important to note the purpose of inertia and center of mass during the execution of this step. When taking off for the grand jete, a dancer must work to keep their torso (primary center of mass) moving in the direction of their anticipated projectile; in other words, the dancer must anticipate the jump. If not, their inertia will resist this upward change in motion, which will limit the success of the grand jete. Crazy that so much physics goes into this ballet step.