mechanics is a large area of physics which focuses on studyofmovement and rest of the bodies, whether or not they are under the action of forces. Mechanics is divided into the areas of kinematics, dynamicsand static. Practically all movements that take place in our daily lives can be described by the equations in this area.
The study of mechanics is of great importance for a huge range of professions, in addition to being the physics content that is most demanded in the ExamNationalofTeachingAverage (And either). Some professionals deal with it daily, such as engineerscivilians,engineersagronomists,engineersmechanics,engineershydraulic, architects,pilotsinplane, physical and others.
What does mechanics study?
The object of the study of mechanics is the movement, so it is a very extensive study area. Among the various possibilities for study, we highlight some that were developed by research in mechanics:
At planet orbits, satellites and asteroids, described by law of universal gravitation and by the Kepler's laws.
THE trajectoryof rockets, bullets, darts and arrows explained through the equations of projectile launch.
O fluid flow, described by the continuity equation, able to explain the flight of planes as well as the situations hydrostatic, in which the fluids are at rest.
O machine operation simple, such as inclined planes, pulleys, hoists, scales etc.
THE particle trajectory electrically charged moving under the action of electric fields and magnetic, as in the aurora borealis phenomenon.
bodies in free fall or even bodies that fall accelerated by gravity, but suffer the action of air resistance.
Lookalso:Learn how to solve kinematics exercises
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While studying physics, you may come across the term mechanicsclassic, such term relates to knowledge of the area that is applicable exclusively to situationsmacroscopic. For the other cases, which require an explanation of the movement of tiny particles, such as atoms and molecules, another type of mechanics is used, called quantum mechanics.
In addition to classical mechanics and quantum mechanics, there is the relativistic mechanics, a branch of physics stemming from the discoveries of physicist Albert Einstein. This branch of mechanics studies the behavior of bodies moving at speeds close to the speed of light.
kinematics
kinematics is the field of mechanics that studies the movement of bodies without taking into account the causes of this movement. In other words, we study situations that occur from the moment a body starts its state of movement.
In the context of kinematics, which is seen in high school, the following types of movement are studied:
uniform movement
uniform movement is one in which the speed of a body is constant, traveling only in a straight line. The main equation used to study uniform motion is the hourly function of position, shown below:
evenly varied movement
evenly varied movement is the name given to the type of movement in which the speed of a body changes at constant rates. In the case where the movement has its speed increased, we say it is a movementaccelerated, if the speed decreases, we say it is a movementretarded.
At most important equations for the description of uniformly varied motion are the hourly functions of position, velocity and Torricelli equation, check each of these equations now:
uniform circular motion
Circular motion is the one where the direction of speed of a mobile constantly changes, so that your distance to a point of space stayconstant. Even though it is called a uniform circular motion, this motion is accelerated, since, in order to describe a circular trajectory, it is necessary the existence of a centripetal acceleration.
In the study of circular motion, we come across a large number of equations, as they exist: equations that calculate displacement and velocityclimb; equations that calculate greatnessesangular, such as velocityangular; and, finally, equations that serve to relate these two types of quantities.
Check out some of the most important circular motion equations:
uniformly varied circular motion
MovementCircularevenlymiscellaneous (MCUV) is a slightly more general case of the MCU. In it, in addition to a accelerationcentripetal, there is accelerationsangular and tangentialconstants, that cause the angular velocity of the mobile to vary uniformly. As we do in uniformly varied motion, in the MCUV study we use very similar hourly functions of position and velocity, check out:
See too:What is mechanical work?
Dynamics
At dynamics the causes that gave rise to some movement are studied. In this sense, we study the forces that act on a body, the amounts of movement, the mechanical energy, the impulse and the quantities related to rotational movements, such as the torque it's the timeangular.
The bases of the study of the dynamics of High School are the threelawsinNewton, based on them, the other equations of the subarea are derived., and also from kinematics. Check out some of the most important formulas used in the study of dynamics:
static
Statics studies the equilibrium conditions in bodiesextensive, that is, it determines what the measurements or the intensity of forces and torques must be so that a body of non-negligible dimensions can remain in equilibrium. In the study of statics, Newton's laws are widely used.
Mechanics at Enem
Among all areas of physics, mechanics is the one that is most present in ENEM questions, so it is very important that you are able to:
understand O meaning behind kinematics equations, being able to relate them to real situations as well as their graphics;
identify and classify progressive, regressive, accelerated and uniform movements;
understand the concept of referential and understand what relative movements are;
know how to apply Newton's three laws in the most different contexts;
understand the concept of mechanical, kinetic and potential energy and knowing how to operate with these quantities;
do collision calculations using the amount of movement as well as the conservation of mechanical energy;
know and understand the functioning Kepler's laws and their relation to the law of universal gravitation;
understand how they should be applied the static equilibrium conditions to bodies whose dimensions cannot be neglected;
understand the causes and effects of particle movements and knowing how to describe them in the form of equations.
See too: Nuclear physics - study of the constituent particles of the atomic nucleus
By Me. Rafael Helerbrock
Kinematics is the area of mechanics that studies the movement of bodies without taking into account their causes. Calculate the average speed of a body, in m/s, that travels along an 18 km avenue during a 6-minute time interval.
A body with a mass equal to 10 kg moves by the action of a net force F, with an acceleration of 2.5 m/s². The modulus of the resulting force on this body must be equal to
