What is kinematics in physics?
Kinematics is that branch of Newtonian mechanics that deals with quantitatively describing the motion of bodies, resorting exclusively to the notions of space and time, regardless of the causes of the motion itself, a task instead of dynamics.
Length, time, displacement, mass, speed, acceleration, temperature, force, work ...
KINEMATICS (from the Gr. Κίνημα "movement"). ... Motion in relation to such circumstances deals with mechanics proper or dynamics (v.), Which includes, as a more particular theory, statics (v.), Which investigates the conditions in which given material systems are they keep quiet.
The movement of a material point
Kinematics studies how the position of an object changes over time. ... The Cartesian reference system is the best method to study the motion of a point. The reference system consists of: 3 Cartesian axes, perpendicular to each other.
kinetics Part of mechanics that studies motion phenomena, in relation to the material constitution of the bodies involved in the movement and to the quantities (kinetic energy, kinetic moments, etc.) relating to them.
In physics, dynamics is the branch of Newtonian mechanics that deals with the study of the motion of bodies starting from its causes (forces) or, in more concrete terms, the circumstances that determine and modify it in the time and space of its reference system.
The statics is the part of mechanics that studies the balance of a material body, that is the conditions necessary for a body, initially at rest, to remain at rest even after the intervention of external forces.
In physics, acceleration is the change in speed in a motion. It can be medium or instant. What is the difference? The average acceleration detects the speed variation of a moving point over a time interval (t-t0), while the instantaneous acceleration detects it at a precise instant (t).
The hourly law of a body is the relation that binds the instant of time t and the position s of the body to that instant. ... In some very important cases, the hourly law is a function s = s (t) which allows to calculate the position s of the body at a given instant t.
If the motion is characterized by constant velocity, that is, it is a uniform rectilinear motion, then the average and instantaneous velocity coincide at every instant of time or interval considered throughout the motion.
We speak of various motion when the velocity vector is a vector that changes continuously in magnitude and direction (we deduce that the trajectory and velocity vary over time, that is, the acceleration varies over time).
This entry on the subject of physics is only an outline.
In physics and geodesy a reference system is a system against which a certain physical phenomenon or physical object is observed and measured or certain measurements are made.
Modern kinematics was born with the studies of Galileo Galilei, but its modern definition, which uses the principles of infinitesimal calculus, can be dated to the allocation by Pierre Varignon on January 20, 1700 in front of the Royal Academy of Sciences in Paris.
Space is the length of the trajectory traveled by the moving body. Time is the duration of the motion of a body. Speed is the distance traveled in a unit of time. If the speed is kept constant throughout the course, there is uniform motion; if, on the other hand, the speed is variable, there is a variable motion.
A scalar quantity is defined by a real number with dimensions. Examples: mass, time, energy, pressure ... A vector quantity is defined by a modulus (non-negative real number with dimensions), a direction and a direction.
Therefore, the hourly law of uniform rectilinear motion is: S (t) = V · t + S0, where: V is the speed, always constant.
The hourly law of a uniform rectilinear motion is graphically represented by a straight line passing through the first quadrant. In order to draw this line, at least two points are required to be shown in the diagram. (0; 1) and (2; 2).
The position of a body is identified through the coordinate of its center of gravity. A single measurement does not tell us if the depicted cat is stationary or moving: the only way to know is to make several observations over time and see if the position changes. To study motion, therefore, you need a stopwatch.
Formulas of uniform rectilinear motion
In the example of the car, and more generally in any uniform rectilinear motion, if we want to know the position of the material point as time varies (therefore the space traveled as a function of time) we can make use of the hourly law of uniform rectilinear motion .
In general, the symbol A is used precisely to indicate variations, i.e. a given quantity at a certain instant minus the same quantity at a previous instant). v (t) = dx / dt, the instantaneous acceleration is the second derivative of x (t), i.e. a (t) = d dt dx dt = d2 x dt2 = ˙ ˙ x (t).
The average acceleration in Physics is a vector quantity given by the ratio between the speed variation of a body in a time interval and the time in which this variation occurs. More simply, it is often referred to as the relationship between speed and time.
Therefore: the instantaneous acceleration is the limit value of the average acceleration ΔV / Δt around a given instant, when Δt → 0 (i.e. the time interval Δt becomes so small that it tends to zero).
Static: studies the bodies in equilibrium, that is those particular cases in which the acting forces are balanced. Equilibrium can be static (the system remains stationary as a whole) or dynamic (the system moves with uniform motion).
Characteristics of a static force
Static forces are those forces applied to the material in a constant way or those forces that vary very slowly over time. However, their application time must be greater than 60 seconds.
A material point persists in its state of rest or uniform rectilinear motion if the resultant of the forces applied to it is a null vector. (i.e. if the forces oppose and cancel each other out).