Ways To Increase Kinetic Energy

Kinetic energy is the energy of motion; it is the energy expressed by moving objects. Whether you are looking for a longer golf drive or a more powerful tool, kinetic energy can help you achieve your goal. Increasing kinetic energy is all about manipulating its two key components: mass and velocity.

Translational kinetic energy is the energy of motion in a straight direction — think of it as the energy of a car driving down the street. Kinetic energy is a function of the object's mass and its velocity. More specifically, translational kinetic energy can be described as one-half times the mass times the square of the object's velocity: 1/2mv^2.

Because the translational kinetic energy formula consists of only two variables, mass and velocity, increasing one of those properties is the only way to increase an object's translational kinetic energy. Increases to mass and velocity, however, do not have the same impact. Because kinetic energy is proportional to the velocity squared, increases in velocity will have an exponentially greater effect on translational kinetic energy. Doubling the mass of an object will only double its kinetic energy, but doubling the velocity of the object will quadruple its velocity.

Rotational kinetic energy describes the energy of an object rotating around a center of gravity — for example, a rider on a Ferris wheel. In this case, kinetic energy is a still a function of mass and velocity, but the terms used are slightly different to account for the movement in a circular direction. Rotational kinetic energy applies the same equation, except the mass term is replaced by a variable known as the "moment of inertia," (I), while the velocity term is replaced by the object's "angular velocity," (w) — 1/2Iw^2.

As with translational kinetic energy, increasing the energy is a matter of increasing mass and velocity. The "moment of inertia" is equal to an object's mass times the square of its distance from the center of rotation, so it can be increased by either increasing the object's mass or moving it farther from the center of rotation — simply build a bigger Ferris wheel. Alternatively, you can increase kinetic energy by increasing the angular velocity, which means simply increasing the speed at which the object rotates around the center of rotation.