Statics is the science of methods for quantifying the force of interaction between bodies. These forces are responsible for maintaining balance, moving bodies or changing their shape. In everyday life, you can see many different examples every day. Movement and shape changes are critical to the functionality of both man-made and natural objects.
The concept of statics
The foundations of statics were laid over 2200 years ago, when the ancient Greek mathematician Archimedes and other scientists of that time were studying amplifying properties and inventing simple mechanisms such as a lever and an axle. Statics is a branch of mechanics that deals with the forces that act on bodies at rest under the condition of equilibrium.
This is the branch of physics that makes possible the analytical and graphical procedures needed to define and describe these unknown forces. The section "statics" (physics) plays an important role in many branches of engineering, mechanical,civil, aviation and bioengineering, which deal with the various effects of forces. When the body is at rest or moving at a uniform speed, then we are talking about this area of \u200b\u200bphysics. Statics is the study of the body in balance.
The methods and results of this branch of science have proved particularly useful in the design of buildings, bridges and dams, as well as cranes and other similar mechanical devices. To be able to calculate the dimensions of such structures and equipment, architects and engineers must first determine the forces that act on their interconnected parts.
Axioms of statics
Statics is a branch of physics that studies the conditions under which mechanical and other systems remain in a certain state that does not change with time. This section of physics is based on five basic axioms:
1. A rigid body is in a state of static equilibrium if two forces of the same intensity act on it, lie on the same line of action and are directed in opposite directions along the same line.
2. A rigid body will remain in a static state until it is affected by external forces or a system of forces.
3. The resultant of two forces acting at the same material point is equal to the vector sum of the two forces. This axiom obeys the principle of vector summation.
4. Two interacting bodies react to each other with two forces of equal intensity in opposite directions along the same line of action. Thisthe axiom is also called the principle of action and reaction.
5. If a deformable body is in a state of static balance, it will not be disturbed if the physical body remains in a solid state. This axiom is also called the solidification principle.
Mechanics and its sections
Physics in Greek (physikos - "natural" and "physis" - "nature") literally means the science that deals with nature. It covers all known laws and properties of matter, as well as the forces acting on it, including gravity, heat, light, magnetism, electricity and other forces that can change the basic characteristics of objects. One of the branches of science is mechanics, which includes such important subsections as statics and dynamics, as well as kinematics.
Mechanics is a branch of physics that studies forces, objects or bodies that are at rest or in motion. It is one of the largest entities in the field of science and technology. Tasks in statics include the study of the state of bodies under the influence of various forces. Kinematics is a branch of physics (mechanics) that studies the movement of objects, regardless of the forces that cause the movement.
Theoretical mechanics: statics
Mechanics is a physical science that considers the behavior of bodies under the action of forces. There are 3 categories of mechanics: absolutely rigid body, deformable bodies and liquid. A rigid body is a body that does not deform under the action offorces. Theoretical mechanics (statics - part of the mechanics of an absolutely rigid body) also includes dynamics, which, in turn, is divided into kinematics and kinetics.
The mechanics of a deformable body deals with the distribution of forces inside the body and the resulting deformations. These internal forces cause certain stresses in the body, which can eventually lead to a change in the material itself. These issues are studied in strength-of-materials courses.
Fluid mechanics is a branch of mechanics that deals with the distribution of forces within liquids or gases. Fluids are widely used in engineering. They can be classified as incompressible or compressible. Applications include hydraulics, aerospace and many more.
The concept of dynamics
Dynamics deals with force and movement. The only way to change the movement of a body is to use force. Along with force, dynamics studies other physical concepts, among which are the following: energy, momentum, collision, center of gravity, torque and moment of inertia.
Static and dynamic are completely opposite states. Dynamics is the study of bodies that are not in equilibrium, and acceleration occurs. Kinetics is the study of the forces that cause motion, or the forces that result from motion. Unlike such a concept as statics, kinematics is the doctrine of the movement of a body, which does not take into account the fact thathow the movement is made. It is sometimes referred to as the "geometry of motion".
Kinematics
Kinematic principles are often applied to analyze the determination of position, velocity and acceleration in various parts of equipment during its operation. Kinematics considers the motion of a point, a body, and a system of bodies without considering the causes of motion. Motion is described by a vector of quantities such as displacement, velocity, and acceleration along with an indication of a frame of reference. Various problems in kinematics are solved using the equation of motion.
Mechanics - statics: fundamental quantities
The history of mechanics spans more than one century. The basic principles of statics were developed a long time ago. All kinds of levers, inclined planes and other principles were needed during the early civilizations to build, for example, such huge structures as the pyramids.
The fundamental quantities in mechanics are length, time, mass and force. The first three are called absolute, independent of each other. Force is not an absolute value as it is related to mass and changes in speed.
Length
Length is a value used to describe the position of a point in space relative to another point. This distance is called the standard unit of length. The generally accepted standard unit for measuring length is the meter. This standarddeveloped and improved over the years. Initially, it was one ten-millionth part of the earth's surface quadrant, with which it was quite difficult to make measurements. On October 20, 1983, the meter was defined as the length of the path traveled by light in a vacuum in 1/299.792.458 of a second.
Time
Time is a certain interval between two events. The generally accepted standard unit of time is the second. The second was originally defined as 1/86.4 of the Earth's mean rotational period on its axis. In 1956, the definition of a second was improved to 1/31.556 of the time it takes for the Earth to complete one revolution around the Sun.
Mass
Mass is a property of matter. It can be thought of as the amount of matter contained in the body. This category defines the effect of gravity on the body and resistance to change in movement. This resistance to change in motion is called inertia, which is the result of the mass of the body. The generally accepted unit of mass is the kilogram.
Power
Force is a derived unit, but a very important unit in the study of mechanics. It is often defined as the action of one body on another, and may or may not be the result of direct contact between bodies. Gravitational and electromagnetic forces are examples of the result of such an impact. There are two principles of influence, of forces that tend to change the movements of the system and that tend todeformations. The basic unit of force is the Newton in the SI system and the pound in the English system.
Equilibrium equations
Static means that the objects in question are absolutely solid. The sum of all forces acting on a body at rest must be equal to zero, that is, the forces involved balance each other and there should be no tendency for forces capable of turning the body around any axis. These conditions are independent of each other, and their expression in mathematical form constitutes the so-called equilibrium equations.
There are three equilibrium equations, and therefore only three unknown forces can be calculated. If there are more than three unknown forces, it means that there are more components in the structure or machine than are required to support certain loads, or that there are more restrictions than necessary to keep the body from moving.
Such unnecessary components or constraints are called redundant (for example, a table with four legs has one redundant), and the system of forces is statically indeterminate. The number of equations available in statics is limited, since any rigid body remains solid under any conditions, regardless of shape and size.
