Kinetic Energy - What is it?
The term kinetic energy is derived from the Greek word for motion, kinesis, and the Greek word for active work, energeia. Therefore, it means through motion do active work. The terms “kinetic energy” and “work” and their present scientific meanings date back to the mid nineteenth century. Early understandings of these ideas can be attributed to Gaspard-Gustave Coriolis who in 1829 published a paper outlining the subject and the mathematics behind it.
There are different types of energies—chemical, heat, electromagnetic, mass, nuclear, and kinetic energy.
These forms of can often be converted to other forms. Kinetic energy can be best understood by examples that demonstrate how it is transformed from other forms of energies to another form. For example, a cyclist will use chemical energies that is provided by food to accelerate a bicycle to a certain speed. This speed can be maintained without further work, except to overcome air-resistance and friction. The chemical form has been converted. However, the process is not completely efficient and heat is also produced within the cyclist.
The energies in the moving bike and the person riding the bike can be converted to other forms. For example, the cyclist could encounter a hill just high enough to coast up so that the bike comes to a complete halt at the top. The activity has now largely been converted to gravitational potential energies that can be released by freewheeling down the other side of the hill. (There are some frictional losses so that the bike will never quite regain all the original speed.) The bike would be traveling more slowly at the bottom of the hill because some of the activity has been diverted into making electrical power. Another possibility would be for the cyclist to apply the brakes, in which case the activity would be dissipated as heat.
In classical mechanics, the kinetic energy of a “point object” (a body so small that its size can be ignored) is given by the equation where “m” is the mass and “v” is the speed of the body. Note that the kinetic energy increases with the square of the speed. This means that if you are traveling twice as fast, you need to lose four times as much stamina to stop.
Another example shows that kinetic energy can be passed from one object to another. In the game of billiards, the player gives kinetic energy to the cue ball by striking it with the cue stick. If the cue ball collides with another ball, it will slow down dramatically and the ball it collided with will accelerate to a speed as the energies are passed on to it.
For more information, explanations, and equations regarding kinetic energy, search online.