The subject of mechanics has many faces, and one of those faces is motion. Motion is the capacity of an object to change its location, direction of motion, speed, or any combination of these. It is an inevitable reality, because all objects have no innate, unlimited, and perfect force that acts without affecting any other forces or objects. For instance, even the planets in the solar system move. The only exception is that the moon doesn’t change its position at all, just the tides.
Because all objects have motion, it follows that there must be a relationship between their motion and that of other bodies. This relationship is called kinetic energy, or the product of mass and velocity. Kinetic energy is used in a variety of scientific disciplines, including how to manufacture practical applications, how to understand the behavior of nature, how to design machines, and how to build and function of our human systems. One of the most fundamental relationships found between motion and the environment is that of the relation of acceleration to time. The concept of angular momentum came from mechanics.
Classical mechanics recognizes three distinct forms of motion: mechanical, kinetic, and potential. All other forms of motion are considered to be combined forms of classical mechanics. Kinematics, which deals primarily with objects in motion, is one branch of mechanics that relies heavily on the concept of momentum. It uses specialized equations to describe motions, such as those governing the motion of pairs of objects in two different directions.
Many people think that mechanics have only a limited practical application. After all, what good is a theory, when it can’t be put to practical use? That’s where applied mechanics comes in. Applied mechanics is essentially a branch of mathematics that applies what has been learned about mechanics to real physical systems. Applied mechanics is used to predict the behavior of all kinds of bodies so that scientists can test their predictions and learn about the properties of the real world through experiments that take place under controlled conditions.
For example, take the study of mechanics for vehicles. Vehicles drive around on their tires, they travel on their wheels, and they depend on their suspension to absorb and redirect their body movements so that they remain balanced and upright. Applied mechanics may be able to study these motions at various speeds and for different lengths of time, determining what the properties of these materials are under various conditions.
One good example of a branch of physics that is not widely known is energy physics. Here, mechanics is used to study the effects of external energy on physical processes, such as the way that heat moves through a material or the way that an electric charge flows from a higher power source to a lower one. Although this branch of science has many interesting areas of research, it has also been successful in generating many great inventions. One of the most prominent examples is the battery. It may not seem like a big deal now, but fifty years ago, if you didn’t have a reliable source of batteries, you would have quite a few problems with your motor car.
One more branch of mechanics that has a real practical application is kinematics. Kinematics is a field that studies how a system moves through space, taking into consideration both kinetic energy and potential energy. This branch of mechanics is especially important in rocketry and aerospace engineering. Since the motion of various materials through space is vital to the performance of a launch, it is important for engineers to understand kinematics. A good example of a kinematic’s experiment is one that tests the effects of G force on an aircraft’s motion at various angles.