There are different Types of force Depending on its meaning, magnitude or intensity, application and direction.
Force is any agent that has the ability to modify the state in which a body is found, regardless of whether it is in motion or at rest. The force can also be an element that causes the deformation of a body. There are natural and derived forces, then we define them:
Types of forces
In the field of physics can be defined as a vector quantity that is responsible for measuring the intensity of the exchange of linear momentum between elements. To measure force it is necessary to know its units and values, but also the place where it is applied and towards which direction.
To represent the strength of graphic form, one can choose a vector. But it must have four basic elements: sense, point of application, magnitude or intensity and straight line of action or direction.
There are several types of forces, some referred to as fundamental forces of nature and others that are expressions of these basic interactions.
Fundamental forces
• Gravitational force
This is one of the best known forces, especially since it was one of the first to be studied. It is the force of attraction that is generated between two bodies. In fact, the weight of a body is due to the action exerted by the earth's gravitational attraction on it. The force of gravity is conditioned by both the distance and the mass of both bodies.
The law of universal gravitation was discovered by Isaac Newton and was published in 1686. Gravity is what allows the bodies to fall on Earth. And it is also responsible for the movements that are observed in the Universe. That is, the fact that the Moon orbits the Earth or that the planets orbit around the Sun is a product of the gravitational force.
• Electromagnetic force
The second force of everyday type is the electromagnetic interactions, which include the electric and magnetic forces. It is a force that affects two bodies that are electrically charged. It is produced with greater intensity than the gravitational force and in addition, it is the force that allows the chemical and physical modifications of the molecules and atoms.
The electromagnetic force can be divided into two types. The force given between two charged particles at rest is called an electrostatic force. Unlike gravity, which is always a force of attraction, force can be both repulsive and attractive. But when the force arises between two particles that are in motion, another force called magnetic is superimposed.
• Strong nuclear interaction
It is the strongest type of interaction that exists and is responsible for keeping the components of the atomic nuclei together. It acts in the same way between two nucleons, neutrons or protons and is more intense than the electromagnetic force, although it has a smaller range. The electric force present between protons makes them repel each other but the great gravitational force that exists between the nuclear particles allows to counteract this repulsion in order to maintain the stability of the nucleus.
• Weak nuclear interaction
Known as a weak force, this is the kind of interaction that allows beta disintegration of neutrons. Its scope is so short that it is only relevant to a core scale. It is a force less intense than strong, but more intense than gravitational force. This type of force can cause attractive and repellent effects, as well as generate modifications in the particles involved in the process.
Derived forces
Beyond the classification of major forces, force can also be divided into two important categories: distance forces and contact forces. The first is when the surface of the bodies involved is not brushed. This is the case of the force of gravity and the electromagnetic force. And the second is a direct contact between bodies that interact physically as when pushing a chair.
Contact forces are these forces.
• Normal strength
This is the force exerted by a surface on an object that is supported on it. In this case, the magnitude and direction of the body are exerted in the opposite direction to the body of which it rests. And the force acts perpendicular and out of that surface. This is the kind of force we see when we support a book on a table, for example. There the object is at rest on the surface and in that interaction are the weight and the force of contact the only ones that act.
• Applied force
In this case, it is the force that an object or a human being transfers to another body, whether this other object or another human. The applied force always acts directly on the body, which means that direct contact always occurs. This is the type of force that is used when kicking a ball or pushing a box.
• Elastic force
This is the type of force that occurs when a spring, compressed or stretched, seeks to return to its state of inertia. These kinds of objects are made to return to a state of equilibrium and the only way to achieve this is through force. Movement occurs because this type of objects stores an energy called potential. And it is this that exerts the force that returns it to its original state.
• Magnetic force
This is a type of force that comes directly from the electromagnetic force. This force arises when the electric charges are in motion. The magnetic forces depend on the velocities of the particles and have a normal direction with respect to the velocity of the charged particle on which they exert their action. It is a type of force that is linked to magnets but also to electric currents. It is characterized by producing attraction between two or more bodies. In the case of magnets, these have one end south and one north, and each of them attracts the opposite ends to themselves in another magnet. Which means that as long as the equal poles repel, the opposites attract. This type of attraction also occurs with some metals.
• Electrical power
This is the type of force that occurs between two or more loads and the intensity of these will depend directly on the distance that exists between these loads, as well as their values. As in the magnetic force with equal poles, charges with the same sign will repel each other. But those with different signs will attract. In this case, the forces will be more intense depending on how close the bodies are to each other.
• Frictional force
This is the type of force that occurs when a body slides on a surface or attempts to do so. Friction forces never help the movement, which means they oppose it. It is basically a passive force that tries to delay or even prevent the movement of the body, regardless of the direction taken.
There are two types of frictional force: the dynamic and the static. The first is the force that is needed so that the movement of two bodies interacting with each other is uniform. This is the force that opposes the movement of the body. The second, the static force, is that which establishes the minimum force necessary to move a body. This force should be equal to the surface with which the two bodies involved in the movement have contact.
The force of friction plays a fundamental role in daily life. As far as static friction is concerned it is a very useful force, since it is the one that allows humans to walk as they do and is also the one that allows the action of holding a pencil. And without this force would not exist the transport on wheels as it is known today. The same importance has the dynamic friction, since it is the force that allows to stop any body in movement.
• Tension force
This is the type of force that is given when a rope, wire, spring or cable is tied to a body and then pulled or strained. This interaction occurs parallel to the bound object and out of it in the opposite direction. In this case, the value of the tensile force is equivalent to that of the tension of the rope, spring, cable, etc., at the moment the force is applied.
• Aerodynamic drag force
This type of force is also known as air resistance, this because it is the force that is exerted on a body as it moves through the air. The strength of aerodynamic resistance creates opposition for the body to be difficult to advance in the air. This means that the resistance that the object puts is always in the opposite direction to the speed of the body. In any case, this type of force can only be perceived - or perceived more clearly - when it comes to large bodies or when it is moved at high speeds. That is, the smaller the speed and size of the object, the lower the resistance of the object to the air.
• Push up
This is the type of force that occurs when a body is submerged in water or any other liquid. In this case, the body seems to be much lighter. This is because when submerging an object two forces act at the same time. The weight of the body itself, which pushes it down, and another force that pushes it from below upwards.
When this force occurs, the contained liquid rises of level because the body that floats displaces a part of the water. On the other hand, to know if a body is able to float is necessary to know what the specific weight of this. To determine this, the weight must be divided by the volume. If the weight is greater than the thrust, the body will sink, but if it is smaller, it will float.
• Ligature force
If you want to determine the resultant force exerting an action on a particle it is necessary to analyze another type of force, that of ligature. It is said that a material point is linked when there are physical problems that limit its movements. And it is then these physical limitations that are called ligatures. This type of force does not produce movement. On the contrary, its function is to prevent the movements that produce the active forces that are not compatible with the ligatures.
• Molecular strength
This type of force does not have a fundamental character like the first four basic forces, nor does it follow from these. But it's still important for quantum mechanics. As its name indicates, the molecular force is that which acts between molecules. These are manifestations of the electromagnetic interaction between nuclei and electrons of one molecule with those of another.
• Inertia force
The forces to which the body responsible for acting on the particle can be identified are known as real forces. But to calculate the acceleration of these forces requires a reference element that must be inert. The force of inertia is then that which acts on the mass when a certain body is subjected to an acceleration. This type of force can only be observed in accelerated reference systems.
This type of force is what keeps the astronauts glued to their seat when a rocket takes off. And this force is also responsible for launching a person against the windshield of the car during a crash. The forces of inertia have the same direction but a direction opposite to that of the acceleration to which the mass is subjected.
References
- Zemansky, S. (2009). "University Physics. Volume 1. Twelfth edition. Mexico". Recovered from fisicanet.com.ar.
- Medina, A; Ovejero, J. (2010). "Newton's laws and their applications. Department of Applied Physics. University of Salamanca. Madrid". Retrieved from ocw.usal.es.
- Medina, C. (2015). "Push force up". Retrieved from prezi.com.