THE 31 TYPES OF FORCE IN PHYSICS AND THEIR CHARACTERISTICS - PHYSICAL - 2024

There are different types of force depending on their sense, magnitude or intensity, application and direction. The force is any agent that has the ability to modify the state in which a body is, regardless of whether it is in motion or at rest.

The force can also be an element that causes the deformation of a body. In the field of physics it 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 where it is applied and in what direction.

To represent the force graphically, you can choose a vector. But this must have four basic elements: sense, point of application, magnitude or intensity and line of action or direction.

Types of forces in physics

There are several types of forces, some called fundamental forces of nature and many others that are expressions of these basic interactions.

- Fundamental forces

Gravitational force

Newton's pendulum helps to understand the concept of gravitational force.

This is one of the best known forces, especially since it was one of the first to be studied. It is the attractive force 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 universal law of gravitation was discovered by Isaac Newton and was published in 1686. Gravity is what allows bodies to fall on Earth. And it is also responsible for the movements that are observed in the Universe.

In other words, the fact that the Moon orbits the Earth or that the planets orbit the Sun is a product of the gravitational force.

Electromagnetic force

The second everyday force is electromagnetic interactions, which include electrical 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 also, 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 between two charged particles at rest is called the electrostatic force. Unlike gravity, which is always an attractive force, in this the force can be both repulsive and attractive. But when the force arises between two particles that are in motion, another force called magnetic overlaps.

Strong nuclear interaction

It is the strongest type of interaction that exists and is responsible for holding the components of 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 electrical force present between protons causes them to repel each other, but the great gravitational force that exists between the nuclear particles makes it possible to counteract this repulsion in order to maintain the stability of the nucleus.

Weak nuclear interaction

Known as the weak force, this is the type of interaction that allows the beta decay of neutrons. Its scope is so short that it is only relevant at a core scale. It is a less intense force than the strong one, but more intense than the gravitational one. 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 the main forces, the force can also be divided into two important categories: distance forces and contact forces. The first is when the surface of the bodies involved does not rub.

This is the case with the force of gravity and the electromagnetic force. And the second is a direct contact between the bodies that physically interact as when a chair is pushed.

Contact forces are this type of force.

Normal strength

The normal force is that exerted by the table on the hourglass resting on it.

This is the force that a surface exerts on an object that is supported by it. In this case, the magnitude and direction of the body are exerted in the opposite direction to the body on which it rests. And the force acts perpendicular and out of said surface.

This is the kind of force we see when we prop a book on a table, for example. There the object is at rest on the surface and in this interaction, the weight and the contact force are the only ones that act.

Applied force

When a penalty is kicked, an applied force is being exerted on the ball

In this case, it is the force that an object or a human being transfers to another body, be it another 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 used when kicking a ball or pushing a box.

Elastic force

The spring is an object with elastic potential energy.

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 object stores an energy called potential. And it is this that exerts the force that returns it to its original state.

Magnetic force

Magnets give off a magnetic force that allows them to attract certain metals without the need to touch them.

This is a type of force that emerges directly from the electromagnetic force. This force arises when electrical charges are in motion. 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, they have a south end and a north end, and each of them attracts the opposite ends to themselves in another magnet. Which means that while like poles repel each other, opposites attract. This type of attraction also occurs with some metals.

Electric force

If you rub a balloon with your hair, it acquires the property of attracting bodies. That is why this kitten cannot get rid of it.

This is the type of force that is produced between two or more charges and the intensity of these will depend directly on the distance between said charges, as well as on 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 each other. In this case, the forces will be more intense depending on how close the bodies are to each other.

Friction or friction force

This is the type of force that occurs when a body is slid over a surface or is attempted to do so. Frictional forces never help movement, which means they oppose it.

It is basically a passive force that tries to slow or even prevent the movement of the body, regardless of the direction taken.

There are two types of friction force: dynamic and static.

Dynamic friction forces

Ice skates create dynamic friction

The first is the force required for the motion of two interacting bodies to be uniform. This is the force that opposes the movement of the body.

Static friction forces

The second, the static force, is what 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 friction force plays a fundamental role in daily life. With regard to static friction, it is a very useful force, since it is what allows humans to walk as they do and it is also what allows the action of holding a pencil.

Without this force, wheeled transport as it is known today would not exist. Dynamic friction is equally important, since it is the force that allows any moving body to stop.

Tension force

This is the type of force that occurs when a rope, wire, spring, or cable is tied to a body and then pulled or pulled tight. This interaction occurs parallel to the tied object and away from it in the opposite direction.

In this case, the value of the tension force is equivalent to that of the tension possessed by the rope, the spring, the cable, etc., at the moment the force is applied.

Aerodynamic drag force

This type of force is also known as air resistance, because it is the force that is exerted on a body while it is moving through the air. The aerodynamic drag force creates opposition so that the body is hindered from moving forward in the air.

This means that the resistance that the object puts up is always in the opposite direction to the speed of the body. In any case, this type of force can only be perceived - or is perceived more clearly - when it comes to large bodies or when it moves at high speeds. That is, the lower the speed and size of the object, the lower its resistance to 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 appears to be much lighter.

This is because when submerging an object two forces act at the same time. The weight of your own body, which pushes you down, and another force that pushes you from the bottom up.

When this force occurs, the contained liquid rises in level because the floating body displaces part of the water. On the other hand, to know if a body is able to float, it is necessary to know what its specific weight is.

To determine this, you must divide the weight by the volume. If the weight is greater than the thrust, the body will sink, but if it is less, it will float.

Binding force

If you want to determine the resultant force that an action exerts on a particle, it is necessary to analyze another type of force, that of binding. A material point is said to be linked when there are physical problems that limit its movements.

It is then these physical limitations that are called ligatures. This type of force does not produce movement. Rather, its function is to prevent movements produced by active forces that are not compatible with ligatures.

Molecular force

This type of force does not have a fundamental character like the first four basic forces, nor is it derived from them. But it is still important for quantum mechanics.

As its name implies, the molecular force is the one that acts between the molecules. These are manifestations of the electromagnetic interaction between the 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 a referential element is needed that must be inert.

The inertial force is then the one that acts on the mass when a certain body is subjected to an acceleration. This type of force can only be observed in accelerated reference frames.

This type of force is what keeps astronauts glued to their seats when a rocket takes off. This force is also responsible for throwing a person against the car's windshield during a crash. The inertial forces have the same direction but a direction opposite to that of the acceleration to which the mass is subjected.

- Types of forces according to specific parameters

Of volume

Force that acts on all the particles of a given body, such as magnetic or gravitational forces.

Of surface

They act only on the surface of a body. They are divided into distributed (weight of a beam) and punctual (when hanging a pulley).

Contact

The body that exerts the force comes into direct contact. For example, a machine that pushes a piece of furniture.

From distance

The body that exerts the force does not come into contact. They are the gravitational, nuclear, magnetic and electrical forces.

Static

The direction and intensity of the force changes little, like the weight of snow or a house.

Dynamics

The force acting on the object varies rapidly, as in impacts or earthquakes.

Balanced

Forces whose directions are opposite. For example, when two cars of the same weight and going at the same speed collide.

Unbalanced

For example, when a truck collides with a small car. The force of the truck is greater, and therefore they are unbalanced.

Fixed

They are forces that are always present. For example, the weight of a building or of a body.

Variables

Forces that can appear and disappear, like the wind.

Of action

Force exerted by an object that moves or modifies another. For example, a person who hits a wall.

Reaction

The body on which the force is applied exerts a reaction force. For example, a wall, when hit, exerts a reaction force.

References

1. Zemansky, S. (2009). «University Physics. Volume 1. Twelfth edition. Mexico". Recovered from fisicanet.com.ar.
2. Medina, A; Ovejero, J. (2010). «Newton's laws and their applications. Department of Applied Physics. University of Salamanca. Madrid". Recovered from ocw.usal.es.
3. Medina, C. (2015). "Pushing force up". Recovered from prezi.com.